I have a 5.0 tpi motor in my firebird. I was wondering if I could swap a 5.7 tpi block in place of my 5.0 block with out screwing up the ecm. Any help or ideas would be great.

 

From what i understand is all you need is the 350 block of course and change the knock sensor and probably want to go 22 # injectors.

 

And the memcal for the 350 engine.

 

I was able to swap EVERYTHING over from my Lb9 to a 350 block. No ecm problems, no knock sensor problems either. Car ran like a champ and kept up with a L98 vette no problem.

 

Hook up a scanner or a laptop and I garauntee you won't be as happy as you sound right now. You have the wrong memcal, and the wrong size injectors, and almost certainly the wrong knock sensor. You should be lean on the top end due to your injectors and the memcal. The last thing you want is to be lean at high rpm, which is a primary cause of detonation. Which brings up the next point:

The knock filter circuitry is mounted on the memcal itself. It is specific to engine displacement. Will it run with the wrong memcal? It will run, yes, I give you that. Is it a good idea? Nope.

You don't want to use the wrong knock sensor, or wrong memcal. You can get away with the injectors on a stock 350 if you raise the fuel pressure up a bit, and do some tuning.

doc76239, you can do the swap without too much to worry about. The harness and ecm were the same from the 305 to 350, and so are all the intake components. You just need to pick up 22 lb injectors, a 350 memcal, and the correct knock sensor for your application. You have everything else you need in the car already.

 

So how would I know what the right knock sensor would be? I'm trying to keep the engine looking stock and to pass emissions. Plus I figured it would be the easiest swap as far as a direct bolt in. My car is an 89 firebird tpi 305, what would be the best 350 tpi block? Another 89 f-body tpi 5.7 or something out of a vette or? You help keeps me sane, sometimes

 

You can either go to your dealer or local auto parts, and ask for an 89 Camaro 5.7 knock sensor. Before the swap. take lots of pictures of the harness routing right now, and anything else you think might be helpful. When you put it together, you can see exactly how the harness was routed from the factory, and keep it the same.

I just noticed in my post above that I oversaw something. The knock filter circuitry is mounted on the memcal during the 90-92 years only. It wasn't internal during the 86-89 years.

As far as the block, you want any 350 block that has provisions for a hydraulic roller camshaft. To put it simply, make sure that under the manifold in the center of the block, are three "stumps" sticking up and have what looks like a "sheet metal spider" mounted on it. Since your not building anything radical, it doesn't matter if its a two or four bolt main (obviously four bolt is preferable, but not necessary). You can do as I did when I did my 305 to 350 conversion and pickup a 350 out of a truck or van. That would be a 350 TBi engine, aka L05. If you do so, do your self a favor, and don't even consider using the cam or heads from the L05. They are probably the worst possible cam and heads that you can use from the factory. If on the other hand you pick up a block that was originally from a TPI equipped car, then the heads and cam will be much better.

 

I have a friend of the family that is a car auction junkie, he picks up stuff he is never going to fix or use. Any way he has a 90 some thing vette sitting in his yard. He was going to drop the drivetrain into an s-10 pickup, but he has other projects that are more important. I know the motor is tpi and thats about it. It runs like new.The body is shredded to hell. So I could possibly use this engine.

 

That would make a good engine for you to use provided its in good mechanical condition. I believe its going to have aluminum heads, which are quite desireable and a bit expensive as well.