Im building a 455 and I want 450+ hp. Can I do this with 9 to 1 pistons? I really want to drive it during the summer and on pump gas.Thanks for any feedback. Steve

 

I can't tell you for certain, but I think that more information is required:
-Do you plan to pretty much rebuild it stock or what?
-If not what are the additions?

 

From what I have always understood, you can run iron heads up close to 10-1 on pump 97 octain. My cheby big block was about that. No problems. However, it also depends on the cam choice. Steep ramps etc. I am sure that someone will chime in with more experience.

 

Mine is 10,85:1 iron headed and run without problems on 93 octan .

 

I can get you 450hp on 9.5:1, not an issue. Gotta have good heads though.

 

Oops, meant 93 octane

 

I was gonna use an eagle crank and rods,forged aluminum pistons,750 or better carb and if needed edelbrock heads. Im not sure on the cam yet but I want 425-450 or more hp and I was wondering if I can get it with 9 to 1 compression, I wont go over 10 to 1.

 

Again, yes, very doable even without the Eagle crank.

Here's a combo to shoot for;
800cfm carb
Good heads, either redone iron ones or Edelbrocks
Performer, Street Dominator or Torker intake
1 7/8 headers
Roller or Flat tappet cam, say 234/242 on a 110, roughly .570 lift (preferably a roller)
9.50-9.75:1 compression with iron heads, 10.0:1 with aluminum, still very pump gas freindly

You'll be at a solid mid 400 number, I guarantee it.

 

If you're gonna buy crank, rods and pistons anyway, spend a coupe x-ta bucks and go for the 494 stroker kit - less strain on everything.
With the kit, you can get 450 + hp and 550 ft lbs of torque with a medium cam, and stay under 5000 rpm.
Check it out!