Big block or diesel? know any issues...?

[vintage01]

I'm getting ready to start a project and have a couple things in concern. I have two big blocks: 1967 400 from a catalina and a 1969 396 from an impala. Original plan was to put one of these into a swb 2wd truck. However, a friend of mine has captured my interest in swapping for a diesel in a 4wd. I have read for many hours on different threads about the diesel but never gathered all of my answers I needed.

If I did a diesel swap (say maybe the 6.2/6.5) i would want turbo, ps, pb, ac, manual trans, and still not want to completely remod the whole truck to get those components plus the radiator and intercooler. I am by no means a master mechanic. If anyone can shed some light it would be much helpful and appreciated.

Or should I just stick with the bb street toy? lol both would be a blast

[hugger6933]

what are your expectations for this truck? the 6.2 6.5 diesel [and I love those motors,with the exception of the 94 model,] are not gonna provide killer horsepower that you might want however, the torque is gonna be up there plentiful. If your wanting power to play around on the street and just have power to goof with go with the 396 you can change the cam and carb and intake and add headers when installing, and add maybe 75-100 hp to what is already there.

[MARKDTN]

A Catalina 400 is Pontiac engine. You will need to modify mounts and you will need a BOP transmission pattern instead of a Chevy. You would need all the accessories from that engine. The battery is on the opposite side from a Chevy. Don't get me wrong, I love Pontiacs, but if you are not a "master mechanic" you may not want to do that one. If you go with the 396 you can change the 2bbl '69 only intake to a 4bbl and you could change the cam, but if you don't already have a BB in your truck, you will need all accessories and exhaust manifolds/headers (car manifolds may not work). Kinda the same thing with the diesel. You would want to get it complete with all the accessories and brackets. It will bolt to Chevy bellhousing. Still have to modify mounts, but the exhaust manifolds should work.

What is in the truck now? If all you want is fast and fun consider an LS swap or if you don't mind a little less modern an LT1 or Tuned-Port swap. LT1 and Tuned port will both bolt up to existing mounts and transmision. Tuned-Port can use all the original SB accessories and brackets.

Flame away, but no way I swap a truck to a BB in todays environment. If it already has one, I would leave it. But if you are going to all the trouble of a swap, fuel injection will get you reliability, power, and economy all together. My .02

[vintage01]

The truck has no engine, and it used to have a small block, so I was weighing my options. If I put a diesel in it, Im not too concerned with roddin' power. lets face it, diesels are just pretty neat in themselves. I dont need cummins power, just decent mileage and dependability. But the swap is a little daunting for me having never done such an exchange. Ive read quite a few threads cause i was interested in the idea, I just wanted all of the nice bells and whistles to fit as well as i mentioned before. there again comes the uncertainty in my mechanical skills to accomplish such goal. and the only reason I was considering the big blocks is because I have them already and were given to me years back.

By the way guys thanks for your input. it really is taken into consideration

[MARKDTN]

Buy a complete LT1 or Tuned-Port with transmission and you will not look back. They will both bolt right in where your small block was. Or buy a crate long block and put TPI on top of it. Sell your other 2 motors and you can probably mostly finance the deal depending on their completeness and condition. You will be driving way ahead of a Pontiac or Diesel swap. And if your 396 doesn't have accessories, well the brackets aren't cheap.

[chevyman91]

The 6.2 is an almost direct swap the block is almost the same as a SBC just a little wider as I read
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[GASoline71]

You couldn't pay me to use a TPI engine. There are cats that like 'em, but the technology came out in the smogger era of low performance rods.

The Poncho is gonna be more of a pain as mentioned above. The 396 will bolt right in with different engine stands. But rebuilding a 396 is more expensive than rebuilding a 454. The diesel swap would be cool for low end grunt and pullin' power.

I'd sell the Poncho and the 396 and find a 454. Then you can have more torque and hot rod it as well.

Gary

[MARKDTN]

Originally Posted by GASoline71

You couldn't pay me to use a TPI engine. There are cats that like 'em, but the technology came out in the smogger era of low performance rods....

What do you not like about Tuned Port? They bolt right on older stuff. The torque is great. Reliable. Good mileage. Awesome visual appeal. What's not to like? If you want to build big cubic inches or rev high, they are not for you. But for a plain, driver 350 under 5500 rpm I don't see how you get more bang for the buck than TPI. I have 2 of them on vehicles. That said, if I had an empty engine bay and no accessories, I would go LS power. I saw a blurb on a Hot Rod magazine build where they tried to blow one up with twin turbos. Thought it was a 5.3 but it was a 4.8. They got 1200 hp and couldn't kill it!

http://www.hotrod.com/techarticles/h...g_bang_theory/

[Bloodyjaws88]

As far as the TPI goes...I have that setup in both of my camaros. It works well, but dies at around 5k rpm. The LT1 is a good setup too, but you lose low end torque due to the short runners. For my money and simplicity, I'd go with the big block. Yea, you're not going to get.any fuel milage out of it, but a 700R4 with 3.42 or 3.55 gears would help. You guys can call me nuts if you want, I'll run a blig block anyday. I also have a big block waiting to be built.
If you don't intend to use it for daily driver duty...I say go big block. I understand that people want fuel economy, but that's not why we have these trucks is it? That's. just my .02.
Chris
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[Longhorn 70]

B.O.P engines aren't that hard to drop in and fit. You will have to build mounts for the engine but if you are bolting to an auto, adaptor plates are easy to get. I have an OLDS Big Block in my 2wd. It has plenty of tourque down low almost a bit too much. I have been used to advancing camshafts 2-4° to get more bottom end out of them... I ate too many transmissions doing this with the OLDS.

I have wanted to do the L98 TPI in my truck because of the grunt they can have but as stated, they do drop off at 5200 RPM or so. So does the OLDS and so would the stock Pontiac. The L98s do get great economy though due to their fuel management.

Do you want to go fast or pull hard? Maybe you want a well built 383 in there. Good torque for a small block and good HP if built right.

Do you want to use an engine you have on hand? Either would be great and fun.

[vintage01]

Too be honest my only hesitation for using a 350 is that everyone has one. Its one of those "me too" engines. (You got a 350, huh, me too....). Thats why I wanted something different like one of these big blocks. And Im not gonna be afraid to say it but this is my first rebuild of my own. Im a young guy, fresh outta college and like I said earlier, not a master mechanic. I only know what Ive done before. half the time that involves breakin somethin down to fix it on my past vehicles owned, fix the part, and rebuild back the way I found it. Ive built a 49 gmc with my father, but that was simple because it was put back to all original.

Ive gotten a few questions from you guys so I'll answer the few I remember. No it wont be a daily driver, but yes, the better mpg, the more I'll be inclined to drive it. No I dont want it gutless and no fun to drive, but about 10 mpg is by no means "comfortable" to swallow at the pump. I would do a fuel injected engine, but if you toss all that computer and wiring in there its a little over my head is what im afraid of. Ive almost just broke down and thought what the heck, I'll just toss a 350 in it. I could easily do all the stuff i wanted (ps, pb, a/c...etc) mostly because its so often done, and all that info on the "know how" is probably filled in all these threads. And Im sure the truck would get about 15 mpg....? maybe? should I just go this route bein a beginner?

[MARKDTN]

Are the 400 and 396 complete with all the accessories? Do you have a matching transmission? (Pontiac takes a BOP pattern while the Chevy takes a Chevy pattern) If you are using a manual trans, Pontiac flywheels are harder to come by and a BOP bellhousing may not fit a HD 4-sp. Just a few things to think about.

I too used to be deathly afraid of fuel injection. But if you really break it down, it is not that difficult to deal with. Most aftermarket harness have a 3 wire hookup (Ignition, battery, fuel pump) plus ground. The rest of the wiring is also not that bad; computer, 8 injectors, coolant temp sensor, throttle position, MAP sensor, MAF sensor depending on type, maybe canister purge.

If you want an experience, great. But when you put a Pontiac engine in or a diesel, you greatly limit the pool of buyers. You may say you will never sell, but fresh out of college a lot can change. Moving old cars from house to house can be a challenge. Significant others can change your perspective. Now a fuel injected swap also changes your resale pool as well, but IMHO not nearly as much as the Pontic or diesel will.

Just to share a real-world example. I have had an '83 K20 pickup since '91. I bought it with 42k miles. It has 3.42 gears an a 700R4 transmission. It always got 14-15 city and 17-18 highway MPG. To maintain highway speeds with any kind of load, you were always on the gas. At about 150k a cam lobe went down. I swapped the original 180HP 350 4bbl for a bone stock '91 Corvette L98 TPI engine. My mileage is now around 17 city and 21 highway. It maintains speed effortlessly. Low end torque is noticably better. I gathered parts and did the swap in a day.

With an LT1 or TPI you can use stock mounts and a lot of original parts. As I said before though, if I had an empty engine bay today I would go LS power. I would go buy a pullout 5.3 with 4L60E. The LS engines are even better than the early ones. My '01 Tahoe turned 250k miles yesterday. Oil is still brown after 5k miles between changes. I have never had a valve cover off. It doesn't leak any oil anywhere. It has never had a water pump or starter. You can't say that about the original 350s (or diesels or Pontiacs or 396s).

[vintage01]

MARKTDN, were there any issues hooking up to gauges, throttle, anything? And what about the radiator? did you use the factory setup or did you buy one specifically for the later model motor and do some fabrication? And I would want preferably a 5 speed manual, any suggestions on which would be decent price and dependability? Sorry for kickin out all the questions but like I said, new guy here

[MARKDTN]

Originally Posted by vintage01

MARKTDN, were there any issues hooking up to gauges, throttle, anything? And what about the radiator? did you use the factory setup or did you buy one specifically for the later model motor and do some fabrication? And I would want preferably a 5 speed manual, any suggestions on which would be decent price and dependability? Sorry for kickin out all the questions but like I said, new guy here

Gauges, throttle, etc hook up as original. You need an throttle cable from the donor vehicle. Following is a partial writeup that may help on TPI.

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Following is information on TPI swap in a 68-82 Corvette, however much of it is applicable to a 67-72 truck. The big difference is the fuel tank. If you don't mind the tank behind the seat, you can use a stock tank and the Ford external pump. The truck I did was a short bed and he wanted the tank out of the cab. I looked into a 87 truck TBI tank and I think it had clearance issues with the rear suspension (might work on a long bed). I used an '86 S10 Blazer tank from a 2.8TBI vehicle. I even used the fuel lines from this Blazer up to the engine compartment with some re-bending, but they worked pretty well. This put the filler rear and right. He swapped to a stepside bed from a 88-99 pickup and had the body shop swap the filler around. It did require a bit of frame cutting and boxing, but it was all behind the axle mounts. I just swapped the TBI pump to a TPI pump from an IROC Camaro. The TBI tanks work nicely because they use barbs on the hose insead of screwed firttings. Be sure to swap to FI hose and FI clamps, there is a difference and it is important. On the truck, he wanted headers. I despise headers, on my own truck I would use stock manifolds and weld a bung into the exhaust for the oxygen sensor. I mounted the ECM behind the glove box which took up a lot of room. If I ever did another, I would buy a C4 Corvette weatherproof ECM and mount it in the engine compartment instead. This requires a more expensive harness and ECM, but it would help in the cab. On the swap I did, I used C4 Corvette serpentine accessories, which forces you into electric fans because the aluminum water pump cannot stand up to mounting a fan. If you go this route and have A/C, it will require a custom hose. Also, you will want to upgrade to a CS144 alternator, the CS130 is not very reliable. A better (less expensive) alternative is probably 88-95 TBI truck acessories, which would allow a pump mounted fan. If you have any other questions, please ask. This was written almost 10 years ago, so finding good used low-mileage TPI engines is probably not possible now, and the prices are not correct anymore. Just look at the technical info below and ignore those details.
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You have a unit
First you have to determine whether you want mass air flow or speed density. The C3 is more conducive to speed-density due to space issues. Mass-air flow is easier to make engine changes without PROM changes. If you are technically proficient enough to make a Camaro harness work they can be bought for $100 or less. I have been told that you can also use a 3.1 Corsica or Cavailier harness with a little work, it uses the same 7730 Speed-Density ECM. Aftermarket harnesses range from about $300 for Painless to $500 for Howell to $700 for Street and Performance. Howell makes a great harness, but for a Tuned Port they do not make one that will control the converter lockup on a 200R4/700R4/4L60 transmission. If you are running a manual or non-overdrive-automatic transmission I highly recommend them. I have heard great things about Street and Performance harness, but do not have first hand experience with them. I also have a Fuel Injection Specialties (FIS) harness and it is OK. The ECM can be had used for $10-50. A good external fuel pump will cost at least $100. I use an 88 Ford Truck external pump, $114 from CarQuest, made in Texas by Airtech (also available at O'Reileys). If you have a 78-82 you can use your fuel tank with an 82 sending unit and a TPI pump. 68-77 can also use a modified tank or Rock Valley makes a tank for these cars with a baffle and a GM internal fuel pump. Stock 82 tanks do not have a baffle contrary to popular belief. An aftermarket PROM with VATS and Emissions codes removed will be $100-200 depending on source and complexity. You will have to add an oxygen sensor to your exhaust, $20 for the sensor, $5 for the weld-in bung, and say $25 for an exhaust shop to weld it in if you can’t. Some harnesses use VSS and some do not. An auxiliary VSS sensor is around $75. I recommend using VSS to get better drivability. To install a TPI I say figure at least $800 plus the TPI unit and whatever repairs are necessary to bring it up to useable status. I have TPI/700R4 in my 69 Corvette (Howell harness) and an 83 Pickup (FIS harness) and I love it. Starts good, great torque, good fuel mileage, easy to swap onto stock engines (although both of mine are complete engines out of 90/91 ‘Vettes).

Differences in years
All Corvette TPI intake manifolds work with the older (through 86) iron heads and the factory aluminum heads through 91. F-body TPI intakes use the upright center bolts on 87-92 and thus fit all 87-95 iron heads (non LT1). Either can be swapped to fit the other with some drilling. F-body has the fuel lines come out on the drivers side and has a central port for EGR. Corvette has fuel lines that come out on the passenger side and has an external port for EGR. Corvette fuel rails fit F-body intakes and vise-versa. The runners are all the same through the years, but the LH runner has a hole for a 9th injector in the 85-88 runners. This can be plugged off if you get a nice LH runner and don’t want the 9th injector or decide to run speed-density. The plenums all physically interchange, but 90-92 have an extra vacuum port for the MAP sensor used with the speed-density computers and wiring. 89 is an odd year, it is mass-air flow but without the 9th injector. 89 up throttle bodies can be used on all years, but a 85-88 throttle body requires a ½” hole be drilled in the front of a 89-92 Plenum for idle air. 89-92 Throttle bodies have a more desirable cable attachment. The cable attaches around a circular linkage which has a smoother actuation than the straight linkage on the 85-88. The Corvettes have an aluminum plenum extension over the distributor, the F-body extensions are plastic. The Corvettes use an HEI coil-in-cap distributor for 85-91 (Delco 1103680). 85-86 F-body also used a big-cap distributor. 87-92 F-Body used a small cap distributor with an external coil (Delco 1103479). This same distributor is used in the 87-95 5.0/5.7/7.4 TBI injected trucks and pre-LT1 B-body. The F-body intake gets it's exhaust for EGR from the center passages in the heads like most SB Chevys. A Corvette intake gets it's EGR exhaust from the RH exhaust manifold/header through a flex-tube to an opening near the distributor-no center passages in the intake. If you are required to keep EGR and you have a Corvette intake, I recommend getting the C4 exhaust manifolds. They are like mini-headers, and have a 2 1/2" outlet. I have them on my 69 and like them.

As far as a throttle cable to use, on my Vette, I used a TPI Corvette cable, 1990 I think (now discontinued from GM) but you have to cut the end off inside the car and use a hood-release-cable end (Corvette Central 342138 "cable stop") to get it the correct cable length (the housing is OK). You must use a cable from the type car your throttle body came from if you want to have a chance of not cutting it. Again, 85-88 use a straight pull, while 89-92 have a circular attachment for more smooth actuation and so the inner cable is longer. On my 83 truck I used a TPI F-Body cable and it was OK, but I had to coil it up into a loop in the engine compartment because the housing was so long. I also TPI'd a 72 Chevy truck and used a 90 350 TBI truck cable for it. It was 1/2" short outside if anything, but I was pretty pleased with it all told-I didn't have to shorten it. In a Vette it might be about right. In all vehicles I've done you need a die grinder to square the firewall hole off a bit. All vehicles I've done used the late throttle-body.

I would look into a TPI. It will bolt up to everything in your car, use stock accessories, use your transmission, and the visual appeal is awesome. Don't be afraid of fuel injection, it really works.

As far as websites see:
www.corvettefaq.com for conversions or more TPI info at www.fuelinjection.com also www.jagsthatrun.com for misc hard to find conversion parts and info.

LT1
Not to get too deep into the differences in LT1s, there are basically 3 variations. There is the C4 ('92-96) and an F-body ('93-97) version which are 5.7L and have aluminum heads. There is a B-body ('94-96) which is 5.7L with iron heads that actually flow better than stock aluminum heads. There is also a 4.3L B-body (L99) version that you want to stay away from. There is an LT4 in '96 that is an upgraded LT1. All are dimensionally the same as far as bolt-ons. Corvette engines have 4-bolt mains, all others have 2-bolt. All are cast iron blocks. An LT1 is a very similar installation to a TPI. As far as the mechanical installation, the 700R4 and 4L60E transmissions are the same (same length, same basic dimension, mounting, yoke, etc.). You have to have a computer to run a 4L60E which you will have for the engine anyway. As far as the engine, an LT1 will bolt in and can use the same exhaust although you may want to use C4 LT1 manifolds to get true 2 1/2" outlets. The biggest difference between a TPI and an LT1 installation is accessories. TPI can use stock C3 accessories. LT1 has to use LT1 accessories and really needs C4 LT1 accessories. Both F-body and B-body put the a/c compressor low on the passenger side. This interferes with the frame and the right motor mount. You have to use electric fans on an LT1, there are no provisions for a mechanical fan (B-body has an optional one, but it is offset and won't work in a C3). The other difference is in air intake, most LT1s are mass air flow. Again, it is difficult to locate the MAF sensor in a C3. You are better to have it set up for speed-density. In a '78-'82 C3 you could still use an '82 sending unit but an LT1 fuel pump instead. You will want to stay with programming for an OBD1 (pre-'96) style setup, without multiple oxygen sensors. '96-'97 OBD2 engines are fine, you just don't use all the sensors. LT1 requires a custom radiator because of how the hoses run. There are differences in the Optispark, later is better and if you swap to a later cam you can add the later vented Optispark setup. The water pumps are bad to fail and wet the Optispark, so always replace the water pump when you do a swap. LT1s have better top end power that TPIs, but all things considered I'd rather stay with TPI for a cruiser or mild build-I just like the look and the low end torque. If you want more power, LT1 is better; or just step up to an LSx.

[vintage01]

Well it may take some learning curves to do all that, however, I believe over time and with a few questions along the way I'm sure I could get it done. Do you know anything about cummins motors? I have a buddy that has found several 6bt cummins motors with the transmissions. I'm guessing that is a harder swap the complete... But how much harder?