I was considering doing a tpi swap in the summer. Right now I've got the LO3 305 TBI with 170 stock Hp and im probly close to 200 now. I've got a full exhaust with edelbrock headers and ypipe. If I were to do this swap, how much horsepower should i expect from the tpi swap. I'm just curious, i could get it cheap and i can have a friend put it in. Thanks.

 

depends on if you get the MAF tpi or the MAP tpi system. i would look for gains of about 20 hp and 30 hp. it also depends on if you do anything to the tpi system before you have it installed. you can do some port matching, siamese the ports, bigger throttle body, bore the plenum, throttle body air foil, and you might as well throw a cam in there while the intake is off. all of that would probably get you another 30-40 hp

 

Well i was going to get the MAP (speed density) setup and throw a K&N, and a 58mm bbk throttle body. So how much am i looking at with just the stock setup, and also how much with the two mods.

 

if you do a TPI swap get the Stealth Ram intake from Holley. it out flows and is about a 35 hp gain all in itself. you can use everything from a stock tpi on it except the T-Body, you have to use a LT1 T-body, which you find cheap on Ebay.

 

Ok thanks coprunr, but I'm still waiting on an answer to my second question. Thanks.

 

On the early TPI (map)They were 190hp with 9.5:1compression. Yours is 9.3:1. Not a biggy there. But that HP is not just from the tpi. The tpi motor had a different cam than the tbi. And I dont feel a flowmaster and a holley air cleaner giving you 30hp.

 

If you read my original post you would known i have a full exhaust, sorry i didnt update my signiture.

 

I still think 30 is a lot to expect. I would geusstimate 15+/-.
Still respectable gain and sounds good too.
Also less restriction will free up an engines "potential"

 

honestly , not much . the TBI had a sorry excuse for a camshaft.and i have seen a larger T-body do very little on a stock engine, you would gain more by putting a Holley 670 cfm t-body on your stock TBI engine than a putting 58mm on a TPI. ....the biggest draw back of the tbi engine was the camshaft...put bluntly IT SUCKS....if your changing the intake anyway, yank the camshaft and put a LT1 cam in it , you can get good ones on EBAY for like $25 now and the Lt1 camshaft works very well in the TBI and TPI engines.plus while your there you can put a double roller timing chain on it and have the added security that all is well up front. if you change over to a TPI, put a LT1 cam in it, raise the fuel pressure and add a K&N CAI , i'd say 45-50hp gain would be possible.

 

Thanks a lot coprunr that helped a lot. I do have two more questions for you, if i do the swap and put a new cam in will i have to get a upgraded chip to work with my new tpi computer. Also will i need a new fuel pump or do i simply just raise the pressure by a regulator. Thanks.