Hey everyone, I just got my 305tbi rebuilt because i had spun a barring. I was wondering if anyone could help me out with there guess on HP and TQ for my engine now. It has 170HP and 255TQ stock.
305 bored 30 over, raised compression from 9.3.1 to 9.5.1, LT1 cam, 88 iroc 305tpi heads, 3inch exhaust, and a homemade dual snorkel air cleaner.
I'd appreciate anyones best guess and what they think I may run in the 1/4
thanks. Bye

 

By the way I have 3.73 posi in the rear!

 

Be like everyone else, just add up your new mods to the old base numbers and then add a additional 20%=your new Horsepower and Torque numbers to the rear wheels

 

You possibly have about 185 at the crank, i mean 1/2 a point in increased compression isnt gonna do much. The 305 TPI heads arent any good, LT1 cam wasnt necessary, You should of just got 1.6 rocker arms. IMO

 

all of that only got me 15 hp? i thought exhaust would give me that

 

In order to get the best out of the exhaust the induction has to be modified as well. TBI's dont breath that much.

I dont mean to be crude, but you shouldnt have bother rebuilding that TBI.

 

I wanted to build up a 350 but apparently it's real hard to get them to pass emissions here in Ontario. And im only 17 so I needed something with decent gas mileage. Trust me I would have loved to ditch the tbi for something else but I just don't have the money.
Would putting on a bigger tbi unit help out my mods?

 

The LT1 cam does a lot. I dont know what mine did separate, but you're going for lift in the high 300s to the mid 400s, thats more than 1.6 rockers will give you. I think the duration is about 15 degrees longer. Its a proven 4 mph swap. No reason not to rebuild the tbi, if you got it minus well work with it. I wouldnt say that high 14s are out of the question.

Yes, a larger tbi is always a good idea when you do a cam. Its not necessary with stock heads/cam, but IMO when you change the cam you can take advantage of the better flowing 2" tbi. I ran out of money, so thats one of the few things left I need to do. Remember you'll need an intake manifold to accept the larger tbi. Either the Holley Pro-Jection, Edelbrock TBI (bored to 2") or any carb manifold with a Holley TBI adaptor ($12 from PAW). I went with the carb manifold.

 

thats good to know lol
im thinking of doing headers, chip and possible an alluminum intake. that should shave off about another half second right?