I am rebuilding my 330 hp 454 here are the parts I have 4" forged crank forged 7/16 rods bowl blended oval port heads with ss valves performer rpm intake aftermarket ex manifolds and both the stock quadrajet or a holley 850.My question before I order pistons is how much compression can I safely get away with 89 octane and what cam should I put in this thing it is going in my formula 223. Thanks for any help you can give. On a side not if anyone needs a stock 330hp rotating assembly with 400hrs on it I will sell this one cheep.

9 to 1 or maybe 9.5 to 1, no more with iorn heads,hp500 efi cam,holley 850,should be in the 500 hp range.

Are you planning on running a roller cam or a flat tappet cam?

I run mine on 89 with 9 to 1, call RMbuilder for your cam 585-654-8583, he will give you a education on engine building

I second RM builder if your going roller. I think the 850 carb is going to be too large with stock heads. I think 450 hp is about all you'll get with what you have listed. A 750 or 800 would be a good carb for your build. Is your intake for a spreadbore or a squarebore? If its a speadbore this guy can get your quadrajet setup right.
http://www.cliffshighperformance.com

The manifold is set up for both square and speadbore. Does anyone know what size the stock 330 quadrajet is

I was planning on running a hyd flat tappet

It maybe drilled for both but its only designed for one or the other. I believe the stock 330 carb is a 750 cfm.

Do a search for 330 on roids. There is a speed pro cam that a lot of guy's on there really liked. Its a slightly more powerful 420 cam. One of the guys built an engine very similar to what your doing. If you dig you'll find his dyno results.

Here are the dyno results

http://www.offshoreonly.com/forums/g...e-results.html

Thanks alot for the great info it looks like if I want to get close to the 500hp mark I will need some good manifolds or tube style headers