Hello, Im brand new on here. Im not even sure that I am on the right forum. I was told to check it out regarding TBI information. I guess I will jump right into it.

I have a 1970 Chevelle SS. The car is not a clone, however I do not have any of the number matching parts, engine, trans, ets... Anyway, I do have a GEN V 454 with 088 502 heads, ready for assembly. But...I just picked up a 1994 5.7L TBI 350 from a half ton 4x4 truck. I also picked up a 4L60E, complete wiring harness, and computer from a 1993 3/4 ton two wheel drive. I was thinking about just installing this little mouse into my Chevelle to get this car back on the road. It just came home from paint, and the car has not seen black top in 20 years....I am a little itchy to say the least. Anywho, I know I have to get a electric fuel pump to run this enigne. But, I want to run my M21 close ratio 4 speed that is setting in my shop. Will this mess up anything with the computer by not running the 4L60E? Then there is the engine itself. Should I not use the TBI, go with a better set of heads, cam, intake, carb, and dist? My car also has a 12 bolt rear axle with 4.10 gears and a Moroso Brute posi unit. Would this TBI run out of steam in my set up at higher rpm? Im not sure where to start. Todays fuel prices are a factor with the BBC so I think I am leaving that one on the stand for now... Also, will this be a Hyd Roller engine? Thanks and BIG THANKS for any info shared on this forum...

Shawn

 

Shawn - welcome to TGO

Well let see - many questions and too many possibilities.

1) Combining 94 TBI equipped 5.7 with 4L60E, PCM and harness from 93 3/4 ton should not be a problem. First you must locate PCM service number used in 93 donor - most likly it is going to be 16168625 ($E6 Mask) used with AT. I am not familiar with 8625 PCM mask, but it should be able to handle MT with minor mods to calibration. in 93 for manual transmission applications GM used different PCM - (16156480, 16196396 or 16171199) $9A. All of this may mean very little sense at this time, but it is a learning curve that you'll have to master if you wish to play EFI game. 93 is the least desirable year for PCM's - the best would be later 94-95 16197427 ($0D) which can easily handle both MT and AT. Use search - and do some basic research on PCM's mentioned above.

2) TBI can support high RPM - it is the camshaft and exhaust system used in TBI engines that precludes high RPM potential. With enough fuel pressure and right engine parts it is doable, but why??? Street engines almost never see right of 5k RPM.

3) To mix and match parts requires tuning experience - it is not that difficult, but it is not for the timid. There is a huge learning curve involved (PCM).

4) Recommendation - well every one can give you one. Start with simple baseline - use 94 5.7L coupled to 4L60E and make it work with a factory tune in your car. With a free flowing exhaust it should be good for about 250HP and easy to play with. In other words get your feet wet before diving into it head first.

//RF

 

Sorry for the VERY long delay. And thanks for the reply. Im getting ready to look into this TBI 350 more. I know it needs freshing up, but I thought about starting with the basics like you said. Back when I first posted this, gas prices were getting high. But now with the market heading up again for oil prices...$4 gal gas is probably not that far off again. With that said, I am going to make my Chevelle a daily driver for awhile. Anyway now to get into it. I am going to use the TBI 350 along with the 4l60e. I will go out and check the PCM I have in a few and post that too. But since I am going to freshen up my engine, should I go ahead and change the heads, cam, and intake while Im doing it? If I do change those parts, will it still run on the factory tune? I do want to get my feet wet on PCM tunning, but if Im into the engine now, why not go ahead and change those parts right? Anyway, sorry for the delay and thanks again. Everyones input is well worth it. Thanks

Shawn

 

The numbers on the PCM are 16168625

There is also a loose tag with 16186695.

 

Shawn

Before spending a dime and turning a wrench I would suggest that you put together a bill of material (BOM) - including all part numbers and prices. This way you'll quickly discover what your wallet can handle. Sourcing parts and machine shop rates do add-up very quickly (For every engine project I put excel spreadsheet to keep track of costs)!

The P4 PCM (8625) is a very capable power train computer loaded with firmware that can adapt to engine changes. The challenge is to establish a baseline from which PCM can work of. Fortunately, since you are after DD performance wild cam profiles and fire breathing monsters are out of consideration. So for the most part OE VE and SA tables can be used as starting point. Naturally, data logging with WBO or dyno tune would help.

Since this is going to be your DD and fuel efficiency is desired cam and head selection will be on a very mild side. Lets get real DD engine needs low end torque to move 3800 lb vehicle from a stop light to highway speeds. This usually happens with engine operating from 650 to 3500 rpm (95 percent of the time). Also keep this in mind that HP = (Torque * RPM)/5252. So what you need torquee engine for DD operation.

At this time I can not provide you with any recommendations - You need to do basic analysis first before we can dive into part selection discussion.

I hope this gives you enough of starting point.
//RF

 

Exactly put RF. I dont want to go overboard on parts. I had just read where the cyl heads, cam, and intake make this engine suffer. That being said, I figured that I could improve one, two, or all of those components to help with power and fuel economy. Keep in mind, I plan to use the 4.10 rear gear, and thats why I chose to go with the OD trans. Being in a much lighter vehicle, driven properly, I think I can still get the 17 to 18 mpg out of it. Alot better then the 14 to 16 out of the diesel plus the price of diesel fuel is going to be much higher I am afraid... All that being said, I would still like to keep some performance, but if it is going to get into to much $$$$, and affect my MPG all that much, well, then Id be better off dumping the cash into the BBC and go buy a rice burner. But what fun is that right? I mean, how cool would it be driving to work in a fresh black and silver frost 1970 Chevelle SS, with old school Centerline Auto Drag wheels getting decent MPG and still being able to run in the mid to low 14's? Possible I think...

 

I will start on the build sheet as well. Thanks alot RF!

 

One other thing, I could always swap the 93 PCM for the 94 PCM out of the 4x4 truck that I did the enigne swap? Both the doner truck and the 4x4 are both still in my shop. I mean, the engine in the 94 4x4 truck used to be controlled by my 93 PCM, its just one is a 2x4 and the other is a 4x4. Would that be a better PCM to use?