Gen3 Engine Swap- Or not?

[Calitruckgrl1]

The 327 fuelie motor in my '65 GMC has seen it's day, and it's obvious that it is tired out when driving my truck around. I'm not sure exactly when it was put in the truck as I've only had my GMC for about 6 months now.

I got the truck not only because of my love for vintage autos (it was love at first sight), but also to tow my 1972 2-horse trailer that I'm currently restoring to match the truck.

In considering an engine swap, there are so many options it's overwhelming. I just want a reliable tow vehicle. My brother has suggested a 6.0L gen3 engine; other friends have suggested an older 350 or 454 would do just fine. Gas mileage is a concern, but i hope to improve that a little bit anyway when we swap in an overdrive (3sp auto right now).

Any opinions, experiences, or general help regarding my dilemma would be greatly appreciated! Thanks, Sara

[MacAttack]

Sara, I went with the ‘Target Motor’ (350) with my 65’ Chevelle - from having a stock ‘283’ and put an Edelbrock intake and carb and never looked back. I’ve got it hooked to a pumped Powerglide and it’s a stump-puller. Six months on the engine - two oil changes: That’s it. $1600 base price and the top-end stuff from Summit. EVERYTHING else from the ‘283’ bolted right up.

Mac.

[62 short step]

Originally Posted by MacAttack

Sara, I went with the ‘Target Motor’ (350) with my 65’ Chevelle - from having a stock ‘283’ and put an Edelbrock intake and carb and never looked back. I’ve got it hooked to a pumped Powerglide and it’s a stump-puller. Six months on the engine - two oil changes: That’s it. $1600 base price and the top-end stuff from Summit. EVERYTHING else from the ‘283’ bolted right up.

Mac.

I agree, thats probably the best bang for the buck!

[greg64]

Sara, I guess it really depends on how much you want to spend and how many miles you're going to put on. I'm eventually going GenIII in my suburban because I plan to cruise around BC with it, pulling a small trailer. Thus mileage is pretty important. But if you're only going to go a few thousand miles a year, then what's the diff?

Also, I'm glad you're considering the transmission. An overdrive tranny (stick or auto) will make more of a mileage improvement then the difference between a well tuned carb-350 and a gen3.

One thing I can say, I'll bet you'd be happy with the 6.0L gen III once it was done.

[suicide 63]

I've been interested in this swap and i called a local latemodel auto recycler and they priced me a 5.3l and trans with all acc. and ecm for $1300.00 ,50,000 miles on engine.To me this is the only way to go.It sounds like your going to be putting some miles on the truck with a horse trailer so overdrive would be nice. I believe this swap can be done as reasonable as a 350 /700r4 swap.
350 = 1600
700r4= 650 and up newly rebuilt
total = $2250

5.3l and 4l60e = 1300
fuel lines &
tank new = 700
custom tune
on ecm = 200 and up
total = 2200
there are alot of other items to work out motor mounts,wire harness custom or use original ,finishing up the exaust.This engine stock is rated at 295 hp and 325 lb of torque and gets good mileage.good luck Sara hope my ramblings help you decide.

[sailed2japan]

I'm putting a cummins in my 64 panel. I'm thinking it will net me mid 20's fuel milage and still pull 10k lb trailer. I'm setting it up with a3.42 gear and a nv4500 5-spd. guess I really need to start a thread on that here

[billydonn]

If a modern EFI engine with overdrive tranny doesn't violate you sense of vintageness, AND you have the resources ($ and mechanical expertise) to make it happen, that may be the way to go. It would require a new fuel system, probably including relocated fuel tank... so there are technical challenges. FYI you can also put fuel injection on a gen I small block by using Tuned Port parts that came on camaros and corvettes from 85-92. If you just want to keep it simple and inexpensive the 350 crate motor is surely your calling. Good luck.

www.chevythunder.com

[Captainfab]

If it is within your budget and the conversion is within your skill level (or your brother's or someone who can help you) then I would go with a Gen 3. A 5.3 should have enough power for a 2 horse trailer and yet get decent mileage. IMO this swap would also add value to your truck.

The 6.0 would have more power, but I've heard they aren't the best for gas mileage.

[Fastrucken]

My vote is for the Gen III swap, although I'm partial. I aquired my 5.3/ 4l60e with 5k miles and all acc, wiring and computer for 1k, I had to pull it.

Mounting the drive train is the easy part. A set of engine mount adapters from advance adapters, move the auto trans cross member back and have the drive shaft shortened. Thats all there it to physical mounting. I relocated the gas tank to the rear and spent about 250$ doing it. If you or someone you know is good with wiring, then modifying the gen III wiring harness is pretty easy, there's a ton of info on the how. I went with a stand alone computer. 200$ for a upgraded tune is needed for the stock computer. There is not really to much to it.

If your trailor is something that could be pulled behinde a suburban then a 5.3 would suffice with a set of 3.73 gears in the rear end.

Since doing this swap I will never go back and run a old school 350, My 5.3 runs too damn good!!!!


Graham

[ValveTubeHead]

gen1 crate 290hp is an easypeazy all click option...factory new, but greenMileage ain't really its forte.

Weekend wrench

Feb.



Mar.


April


May

[olsofti]

Just do it!

[fchava]

Originally Posted by suicide 63

I've been interested in this swap and i called a local latemodel auto recycler and they priced me a 5.3l and trans with all acc. and ecm for $1300.00 ,50,000 miles on engine.To me this is the only way to go.It sounds like your going to be putting some miles on the truck with a horse trailer so overdrive would be nice. I believe this swap can be done as reasonable as a 350 /700r4 swap.
350 = 1600
700r4= 650 and up newly rebuilt
total = $2250

5.3l and 4l60e = 1300
fuel lines &
tank new = 700
custom tune
on ecm = 200 and up
total = 2200
there are alot of other items to work out motor mounts,wire harness custom or use original ,finishing up the exaust.This engine stock is rated at 295 hp and 325 lb of torque and gets good mileage.good luck Sara hope my ramblings help you decide.

That sounds good, but when I put a 99 vortec w/ 4L60E in my it cost alot more than I planned. I'll admit that I went with all premium parts cause I wanted it dependable.
Custom harness complete from headlites to tails = 1300.00
SS gas tank with internal gm fuel pump = 1000.00
tranny tailshaft to drive a mechanical speedo and the computer = 500
new GM O2 sensers = 250
Etc....etc... etc..
this time for my 66 I chose a vortec again, but with a carb and a non computer 700R4... could not be happier runs like a dream been three years and I would drive it anywhere.[IMG][/IMG]
don't get me wrong, I loved the fuel injection and would love a LS, but don't think that I can do it on the cheap

[suicide 63]

Originally Posted by fchava

That sounds good, but when I put a 99 vortec w/ 4L60E in my it cost alot more than I planned. I'll admit that I went with all premium parts cause I wanted it dependable.
Custom harness complete from headlites to tails = 1300.00
SS gas tank with internal gm fuel pump = 1000.00
tranny tailshaft to drive a mechanical speedo and the computer = 500
new GM O2 sensers = 250
Etc....etc... etc..
this time for my 66 I chose a vortec again, but with a carb and a non computer 700R4... could not be happier runs like a dream been three years and I would drive it anywhere.[IMG][/IMG]
don't get me wrong, I loved the fuel injection and would love a LS, but don't think that I can do it on the cheap

I agree with you that these swaps can nickel and dime you to the poor house thats why I say go with the complete pull out instead of piecing a system together.everyones ability is different,I would use a factory harness,I did for for my tpi setup in my 63. i used a new 87 blazer tank because of the fact it fits in our frames with minor mods and it was the first year of tbi injection so the tank is baffled.It can be had for less than $200 with straps and a sending unit that will accept a intank pump.I ordered 2 of summits 20 ft braided fuel line kits that were rate for high pressure and the an- to metric fittings that i needed for $150.The guages are not a issue for me because i am going to do something custom. Again i admit that issues will arise and will cost money but i would rather dump the money into my project to get the best performance,mileage and reliability than take the easy and or cheap way out and sacrifice mileage and give my money to forgein oil. I do believe that you can acheive the same mileage out of a 350/700r4 combo the fact is that is what i have in my truck its out of a 87 camaro with tpi,but i'm sold on these gen 3 motors I have over 200k on my 01 with no signs of letting up yet.

[sailed2japan]

I agree with you on spending the $ on a good setup rather than spending the cash on low-quality products or even getting something for cheap that isn't really what you want to save a few bucks. And by the looks of the frame, that's gonna be a sweeet set-up.

[fchava]

you are right, suicide and I agree with you completely, but keep in mind that a TPI setup is much simplier than a OBD2 setup and the LS engine/trans.
Your setup looks great should work out well!

[Calitruckgrl1]

Wow guys, there's a lot of really helpful info here you've posted, thanks a ton! The Vortec w/carb and a non computer 700R4 setup sounds appealing while retaining some vintageness to it. I dunno, I'm going to start looking around what's for sale online right now and see what my options are.