Hey guys, could use a little help in trying to determine the HP of my 350. Hopefully I can give you enough information. My 350 block was bored .030 over. I'm not sure about the pistons, only that they are forged with a part number: L2256F, I know not much there to work with. Heads are: 202 intake, 160 exhaust. Cam specs are: Intake @
.50-226. Exhaust @ .50-226. Intake Lift .500. Exhaust Lift .500. TorkerII Intake: Recurved HEI. Match Ports, and header side-pipes. TH 350 Stage II Shift Kit: 2000 stall TC. The machinist/engine builder told me that this combination would produce 425-450 HP. This motor pulls real strong from mid-range on, but lacks a lot at the low end. How much help on the low end would I gain by changing the rear end? I'm now running 307 gears. Oh, and I almost forgot...I used my old, Q-jet, after doing a lot of major overhaul to include multiple attempts at getting the correct jet size.

 

That Torker II is killing your low end torque.

If you want to keep the Q-Jet, get an Edelbrock Performer RPM Q-Jet 7104. Ignore what Edelbrock says about fit. Fits just fine on my '75 with a Moroso low profile aircleaner and 3" filter. I just had to dmple the base a little for the accelerator pump arm.

Different gears will not help the low end, they will just get the engine up into the higher RPM band faster.

As for HP estimates, which heads are you using. Stock '76 heads will choke the engine even with 2.02/1.60 valves. Probably closer to 375 hp with the stock heads. AFR heads are top of the line, maybe 425 hp, maybe. 450 hp, no way.

 

the torker intake is a low rise single plane design.... good for mid range to about 6000 rpm. You could try a good flowing dual plane manifold to restore some bottom end torque without losing the mid and top end.
Obviously, hood clearance will dictate what you could use.

Another suggestion for your low end woes.... you could try a higher stall speed... eg 2800~3000 rpm. This will get the motor into the mid-range sooner, so you can maximise accelleration. OK for dedicated strip cars... but driveability (and fuel consumption) would suffer on the road.

The diff gears are still a concern though. Obviously a ratio like 3.7 will definitely improve torque availability, but once again, rpm at cruising speeds will elevate... increasing moise level, fuel consumption and engine wear.

What do you realistically want to use the car for.... If its for all out performance, choose a diff ratio which will see you crossing the quarter mile near to your max rpm. That way you will get the most benefit out of diff gearing for accelleration.

Engine power ??? who knows. I'd put it on the chassis dyno after installation to know how many REAL neddies you have.
Claimed engine power and real rear wheel power are completely different
Auto trans suck up a lot of power. I'm considering a swap to a manual trans for this very reason.
cheers

tom

 

I think it would be a challenge to get 450hp out of a 350 with that cam. The heads would be the major indicator. If you have stock heads, you could be as much as 75-100hp lower than good aftermarket heads.

 

Thanks for the replies, I believe I am going to change out my Torker II, that way I will no longer need the 1 inch adapter plate to run my Q-Jet. As far as being stock heads, I only know that they were not my originals. The only purpose for my modifications was just to create a saturday night special that could keep up with the older 'vettes. As far as Horsepower, I think that after switching the Torker II out, I need to get my 'vette dynoed, and see what true Horsepower I am running.