[sbarnes]

I have a 69, with a ZZ4 (stock), Holley, cowl induction, t-350, 2,000 stall converter, 3:31 12 bolt, hooker headers, 2 1/2 ex., flow masters. What are your suggestions to increase horsepower? cam, manifold, carburetor, heads, rockers, etc. What, if any changes, would make the most dramatic difference with specific suggestions re Vendors part and part #'s if you can make than type of comment?

[Doug Garland]

Buy the "Hot" LT4 cam that Chevrolet offers,.525 I/E lift w/ 1.6 rockers, 218/228 dur. at .050 lift and put a set of the "Fast Burn " heads on it.You then have basically a ZZ430, just not the limited production #'s one.They only made 430 of those.Nitrous will make the most dramatic increase for the least amount of money.

[sbarnes]

Thanks so much for the reply. Sounds like a good idea, re the rockers, will the stock valve covers work and what about a manifold reccomendation whether or not I chose not to change the cam?

[CarlC]

I agree totally with Doug. The HOT cam kit and fast-burn heads are a great, and well matched, combo. You will need to run a taller valve cover to clear the 1.6:1 roller rocker arms. If you go with the fast-burn heads use GM P/N 12366573. If you are considering this swap check out the GM Performance Parts catalog P/N 12496739. It outlines all of the parts used in the ZZ430 and only costs about $10.

[CarlC]

That's GM P/N 12366573 for the intake manifold. Sorry.

[gheatly]

I would recommend an ATI Procharger centrifugal supercharger. The whole kit (supercharger set-up, modified Holley carb, and modified fuel pump) will run about $3,000. I added one to my ZZ4 (rebuilt with forged blower pistons and a blower cam but with stock everything else) and I dynoed at 506hp at 5,400 RPMs with 9psi.

The whole thing installed in less than a day and a trip to a chassis dyno got it tuned.
The best part is that the blower only adds power under full throttle, so driveability/streetability is excellent. Also, you can't beat the whine of a supercharger.

P.S., I had my ZZ4 rebuilt after 26,000 miles because it burned a quart of oil per tank of gas from the day I put it in the car. These miles were pre-blower. Anyone else had that problem?

[Cardiac]

If you want to make it a ZZ430 check with www.sallee-chevrolet.com These guys have the best prices & build ZZ430 clones by the truck load. You'll need to buy a set of headers for the tall exhaust ports (1 5/8" tall) or use 1 3/4" dia tubes. Tall valve covers are NOT required 'cuz the valve cover rail on the "Fast Burn" heads are raised approx 1/4" Sanderson Performace (1-800-669-2430) is currently building special header flanges for the Fast Burn heads. Thanks to yours truly

------------------
ZZ430 / 4L60E
"Canyon Carver"

[This message has been edited by Cardiac (edited 11-10-99).]