Hey,
I am not on this board much, but I have a cousin who has a '85 Z28 with a stock motor and carb. He wants to get new heads/intake/cam. He wants to go with Vortec L31 heads, a Super Victor intake (for Vortec heads), and a comp Extreme Energy cam. This will be fed by a new Holley double pumper. My question is, is this combo going to do him any good? He is running low 15's with NOTHING done to the engine. Also, any suggestions on where to get decent heads for a decent price?

Thanks,
Dave

 

Well... he'll definitely increase the horsepower of his motor.... but I've got to ask, why not instead.. buy a crate motor? For the cost of the new heads, and all the other work, he's probably looking at what it would likely cost to get a brand new crate 350. Besides that, he would have a completely new bottom end. I always think it's a bad idea when people put new or freshly rebuilt heads on an otherwise high mileage motor. I'm assuming the motor has more than say... 70k miles on it, correct?

It seems a waste of money to spend all of that, only to have your bottom end potentially fail a year or two down the road.

Tell him to spend the extra cash and get a crate 350. You're likely to get much more horsepower.

 

Yeah, I tried to get him to go with the 350. He thinks that he can pull it off (minus the carb) for $800. We looked all around for crate motors, even shortblocks. We couldnt really find anything for less than $1000.
I think he just wants to prove that the 305 can actually go somewhere.

Thanks,
Dave

 

I'm living proof that new heads on a high-mileage bottom end does not spell certain death. 18 months and 16k miles later, it's still running strong. And, it is anything but babied.

The big expense isn't the improvements noted, but what needs to be changed to support the improvements. I don't see any mention of exhaust - a proper street exhaust to support the engine power is going to run $800. And, if you don't know anything else about me, you'll know I'm not a particular fan of the Vortec head craze, especially on a 305 (better shave those heads to keep compression up, which means the intake will need to be shaved to match - bye-bye future use on a 350).

Your cousin could take off the stock heads, do a do-it-yourself porting job, have larger intake valves installed along with upgraded valve springs, screw-in rocker studs, and a "normal" upgrade intake manifold, and produce a big boost in power (along with the cam change) for less money than buying Vortecs (and all that's needed to install them - don't forget as-delivered, they won't support high-lift cams, and need self-aligning rocker arms to boot).

I don't think much of putting a Holley on, either. Any aftermarket carb will require changing the distributor. Your money is better spent on aftermarket coil and module in the stock distributor, and tuning the stock carb. I'm assuming this is a street/strip car - strip-only, then perhaps the Holley can be justified.

 

Thanks a lot guys, I'll be sure to show him this post.
Keep the replies coming if you have anything to add.

--Dave

 

I thought that I saw in a recent issue of Super Chevy or something that they actually lost some power and torque going with the Super Victor intake versus the Performer RPM Air Gap. It was in the power range that most of us would be more likely to use running around on the street. He might want to check out the magazine rack and look into it. The Performer RPM or RPM Air Gap might be a better choice for the street. If I remember right the peak numbers were higher for the Victor but the other drop offs didn't really seem to make it worth it.