'87 4.3 TBI to 5.0 TPI from '87 Firebird

[daveM]

A guy has an 5.0L TPI from an '87 Firebird for sale. Everything but the MASS air flow sensor apparently. Says he has the computer... the works.

Right now my '87 Pick Up has a 4.3 TBI with a TH400. What do you think? Major problems or should I go for it. That motor FI any good for that year? Wants $1500

[piecesparts]

I can relate to this in somewhat of a manner. I am working to put a TPI setup out of a 90 Corvette in my 91 Silverado, which has a 5.7 TBI motor. Some of things that you will need to consider are:

Which tranny does the Firebird engine have? The TPI is setup for that system. If the tranny was a NON-computer unit, then you may have no problem there.

Is the 5.0 in good shape, or is there work needed on it? Consider mileage and internal wear.

Does the 5.0 have ALL of the original accessory brackets? If not, those are getting hard to find as well as, ALL of the necessary bolts. A little creativity may be needed. Do you have the same alternator and A/C design as what was in the car? Look at what would be needed to get the transition done easily. Odds are, your brackets will not work at all on the new motor.

The wiring harness for the TPI will be a monstorous mess and sorting it out is a job that can be done, but you need to get a manual for doing this. If you are adept at doing wiring, then it can be done. If not; then some place like Street and Performance can sell you a harness, but it is not cheap.

How long has the TPI been sitting? The injectors are prone to getting dirty and may cause running problems, once the engine is started. I made a trip to the Arkansas shop of Street and Performance and found out all of the things that I would have to do to have a trouble free install. This also can get pricey, since injectors are about $400.00 new. I have a set of the origninal GM Delphi injectors that will fit your TPI sitting in my basement--and they are clean---If you are interested?


Where did the MAF sensor go? Most aftermarket setups can be cleaned up and the MAF may not be needed, Just the MAP is used on some.

The computer will need to have some things updated or removed to accomplish your swap. Talk to people that do this kind of work and see what is involved.

As for the 87 TPI being a good deal, there is very little difference in yours than the one that I have. The TPI systems had a definite RPM ceiling to them (around 4000 RPM). The performance up to there is great and these units are very popular in streetrods and are good for making HP in a daily driving experience. Where you may fall short is that you have 5.0 motor and the power curve on a 5.7 would be better, but the change from the 4.3 would be phenomenal. The fuel mileage with a TPI is good and programmable. I would recommend getting an aftermarket wiring harness--it woud make the install easy. The computer upgrade is a must do for your project.


OVERALL---you can put a V-8 into the truck , with a carb for a lot less work and investment (IN THE LONG RUN). The tuning could be a lot more simplified and involvement in getting repairs later would be simple. Thinking that if you had a break down on the road somewhere, you would not have to find a mechanic that has equipment to troubleshoot fuel injection over fixing a carb system. However the fuel economy would be better with the EFI setup, theoretically.

The picture below is the TPI that I ended up with in a deal on a streetrod and I am going to install this in my 91 Silverado. The price for the setup that is pictured--with the computer is around $2800.00, according to the guys at S&P.

[Jim85IROC]

The wiring harness won't be too bad to get into your truck. The engine harness is pretty much self-contained... all of the vehicle wiring was on a separate harness, so as long as you mark what all of the connectors are for (assuming you're not familiar enough to identify them without tags), running and hooking up the harness shouldn't be too bad.

You'll need a MAF unless you convert the system to a speed density system, which is a complete waste of time on the 305. As long as you're buying a new MAF, get a Wells SU145. It's a much more reliable unit than any other brand because it doesn't use the original thin-wire format, but the newer style like you'd find in an LT1 MAF.

One thing I would suggest is to toss a somewhat bigger cam into the motor before you install it. The 86 & up 305 TPI cars that were mated to an auto trans got the "peanut" cam which is garbage. The 5 speed cars got the same cam that the TPI 350s got, and it completely transformed the motor.

If you want any additional info on TPI motors, feel free to PM me, or check out thirdgen.org. They'll have more TPI info than you could ever hope for.

[beaterC10]

To put any smallblock in an original V6 truck will also require changing the engine mounts and frame brackets, radiator and shroud, ac lines, and trans cooler lines. If going to a q-jet also have to replace the accelerator cable. I found this out when installing a carbed v8 in my 86 4.3.

[daveM]

Thanks for the info guys. The TPI interested me but I think I'll hold tough for a 5.7L and preferably a doner truck to go with it.

As a quick fix I may replace the heads on the 4.3 (burnt valve) and slap a set of 3.73 gears in her.

[N2TRUX]

Originally Posted by daveM

Thanks for the info guys. The TPI interested me but I think I'll hold tough for a 5.7L and preferably a doner truck to go with it....

Good call. When I read your post I was thinking for 1500 you should be able to find a POS truck/car with a decent motor to use. Part out the donor and recover some of your investement.

Besides there is no replacement for displacement....

[Jonboy]

Along that line, maybe look for a 94-96 Caprice donor car. You would net an LT1 and a 4L60e, and a disc brake rear. I would bet you could probably ebay a lot of the rest off to recoup your investment.

[cckutchma]

Ye i agree with N2Trux. Had an 87 Iroc (POS) with the 305, Had some giddyup for such a light car but was problematic. good call. I have been eyeballing this engine from GM performance. 290 hp 350 for about $1700.00 + S/H Not bad.

[piecesparts]

I am taking my TPI unit and installing a set of vortec heads and a different base to get the better flow characteristics of the vortec. This along with the rocker arm update and bigger flow tubes will make around 300+ HP and change the flat powerband profile to a broader band.

[Jim85IROC]

Originally Posted by piecesparts

I am taking my TPI unit and installing a set of vortec heads and a different base to get the better flow characteristics of the vortec. This along with the rocker arm update and bigger flow tubes will make around 300+ HP and change the flat powerband profile to a broader band.

As long as you're doing that, take a look at the Holley Stealth Ram for vortec heads. That setup is only a couple hundred bucks more than the vortec TPI base, and will give you big gains if you're willing to do a cam swap too. This is the route that I'm taking with my Camaro.

[piecesparts]

Originally Posted by Jim85IROC

As long as you're doing that, take a look at the Holley Stealth Ram for vortec heads. That setup is only a couple hundred bucks more than the vortec TPI base, and will give you big gains if you're willing to do a cam swap too. This is the route that I'm taking with my Camaro.

I guess I would have to ask (Which setup are you looking at that is just a couple of hundred more than the base for the TPI vortec heads (which is around $429.00)? Just about everything I have seen with the word Holley on it starts in the word formation of thousand, rather than hundred. I already have a complete L-98 motor with the TPI unit that has been refurbished to install into a streetrod. However, I am going to change the power curve by going to vortec heads and update the intake and TPI runners, as well as install different rocker arms to update the air flow.

[Jim85IROC]

Originally Posted by piecesparts

I guess I would have to ask (Which setup are you looking at that is just a couple of hundred more than the base for the TPI vortec heads (which is around $429.00)? Just about everything I have seen with the word Holley on it starts in the word formation of thousand, rather than hundred. I already have a complete L-98 motor with the TPI unit that has been refurbished to install into a streetrod. However, I am going to change the power curve by going to vortec heads and update the intake and TPI runners, as well as install different rocker arms to update the air flow.

Holley part number 7542: Vortec Stealth Ram manifold, around $340.
Holley Part number 534-193: Fuel rail kit with adjustable fuel pressure regulator, around $225.

You'll also need a couple fuel fittings and some fuel line to finish off the job. If you go to www.stealthram.com, you'll find a piece-by-piece list of all the parts necessary to replace a stock TPI setup.

You'll lose some low rpm torque with the stealth ram, but at higher rpm you'll get huge horsepower gains, especially if you choose a cam to compliment the HSR.

[SB406]

When / If you go TPI, check out thirdgen.org as Jim85IROC stated. Also, check out moates.net. Here you can get all the goodies to reprogram that bad boy, plus WideBand O2 sensors, etc. I just finished tuning my TBI 406 in my 71. Eventually, I'll get to the LT-1 for my '58.
By the way, Caprice Cop Cars....Great investment. I've taken 2 apart so far......1 LT-1 for my '58, and 1 for my Dad's '71 Maverick (Had a better idea). Hell, the rear end from one is in my '71 GMC now.

[TEAM THC]

I Would Kill To Have A Motor Like That In My Truck

[piecesparts]

I found the vortec head at a machine shop that a buddy of mine has. He bought a used vortec motor for his wife's SUV and then she said she wanted a divorce, so I get the heads, after he finishes the rework and cleanup on them. As long as I pay cash--He wants a little money in the divorce lawyer's fund, I can get them at a really decent price. The heads, TPI base, and runners that I already have are good for a power curve of around 4000 RPM, so by adding the upgrade, I can move that curve to 5500 RPM with an increase of around 80 HP over what I already have.

The original motor and TPI setup was out of a 90 vette and the rating on HP was at 250 HP, so with the injector upgrade that S&P put in and the computer bump, along with what I have planned, I should be hitting well over the 300HP mark and hopefully over the 350 HP level. The latest issue of "Chevy High Performance" magazine had a question in their "Shop Talk" area about the very same thing that I am doing. The discussion lends to the fact that the L-98 is a little weak in top end power and that a set of vortec heads is the cure for this problem. That supports my plans, overall.

[MylilBowTie]

I thought it was to do with the plenum and intake runners that don't flow well at high rpm's 4500+. That is why most that I have seen swap in a LT1 intake and plenum to get the upper rpm flow.

Just an observation I've seen in the past.

[Jim85IROC]

The LT1 intake is another option, but personally I think it looks sloppy because of how the coolant routing is usually handled. The LT1 intake will likely have less low-end torque than the stealth ram due to the lack of any intake runners.

[piecesparts]

I am thinking that I will get what I am after, with what I am doing. Vortec heads, Z28 valves and springs, 1.6 rocker arms, Vortec TPI base, and High flow runners. combined with a MSD multi-spark electronics, headers, and 2 1/2" exhaust. This is combined with a modified computer from S&P with 24 lb injectors. All of this will give me the flow that I am after, as well as the horsepower to make it worth it. There are other avenues, but there are more dollars in my pocket this way.

[SSC's76]

The thread is a few days old and all but.

If you guys do consider this swap in the future make sure your check the classified adds over at TGO. Over the years many 3rdgeners have bought this stuff then lost interest or wrecked thier rides and just want out with a little of thier investment back. It's kinda sad since we loose soo many members that way over there but it's a good source for parts. Just be carefull if you buy direct! PM the Moderator before you send money to see if there has been any problems in the past with the member your getting the items from. We had a few members do some not cool stuff in the past but in general most are good people.

[piecesparts]

So far so good on mine. I now have the L-98 heads off and the Vortecs are going on. I will have to find something to do with the others, now.