So when i take one step foreward in deciding on my combo, i take 2 steps back to make sure it will work in the prime with my set up.
I have narrowed it down to these two head sets and need help deciding:


Airflow Research 180cc Intkake Street heads with 65cc Combustion chamber
and 64 cc exhaust ports HERE
&

Trick Flow 175cc intake Street heads with 56cc Combustion chamber and 67cc exhaust ports HERE


Only these two please. I have a 92 z28 350 TPI 5 speed 3.42 posi rear, bigger injectors, edelbrock headers, stok TPI manifold/runners/plenum.
Please help me decide and let me know why.

Thanks again to anyone who helps,
Boldguy

 

These heads are very different, and if you're going to slap them on you may as well replace a bunch of other stuff at the same time. A new camshaft at least would be something fairly easy/cheap to do at the same time. And there's always the intake manifold.

The AFR heads have about the same size combustion chamber as your stock heads, while the trick flows have smaller ones which will raise your compression ratio and may require the use of higher grade fuel. AFRs also have bigger valves than stock. I don't see much of a benefit in just doing the heads if the rest of your setup will hold you back.

Also, as far as I know there weren't T5 350s made so unless you know for sure your engine is a 350 I wouldn't bother buying any heads for it yet.

 

I've been happy with every set of AFR heads I've used. Everything I bolt them onto makes good power, even very mild combinations. I haven't used those Trick Flow heads so I can't say one way or the other about them.

I'd also ask about that 305/5-speed combo. Factory never put a manual behind a 350 TPI (at least not in an F-body). Everything with a factory 5-speed was a 305.

 

lay across the motor so your head is right beside the dissy

bring a light a little screwdriver and a can of brake clean and look at the back of the block where the engine meets the tranny behind the dr side head

get us that number