460 with 8:1 compression

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Jul 20, 2011 | 09:53 AM

carlmaass

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460 with 8:1 compression

Well I looked up the specs for my '77 460. Turns out it only has a 8:1 compression ratio. Ouch! I was hoping for something around 9 or 9:1. It has the stock D3VE-A2A heads.

Is there any way to bump up the comp ratio to give me a little more torque other than milling the heads? I'd rather not mess with the valvetrain angles. I could find some D0VE heads?...Domed pistons?...

This 460 will be an occasional tow/hauler and needs to run on pump gas. I'll throw in an RV cam, but I've read from a few posts that I might not be able to fully utilize a higher performance cam due to the lower comp ratio.

Exhaust porting and headers will also be additions.

Thanks for any advice.

Jul 20, 2011 | 10:40 AM

mark a.

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Milling D3 heads won't raise it enough to make a difference and putting DOVE heads on without zero decking it will probably make it a pinger. One real problen with big blocks is the pistons are way too far in the hole. I used the 6cc dished 88-93 pistons, took .032 off the blocks deck, that put the pistons at around .005-.008 in the hole and milled my D3's to 95cc that made it close to 9.5:1

Jul 20, 2011 | 03:05 PM

Thunderbird7480

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Joined: Feb 2011

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From: Moore, OK

mark is right. Im working on a build and already went through all these numbers my self.

I have a set of D0VE heads in my truck now. The engine is from a '70 Lincoln. I run 91 octane in it just fine with no pings except up steep hills. I would imagine this would be more pronounced if I were towing.

Anyways, the problem with the D0VE heads is that the difference is so drastic. It doesnt just bump the compression a little. My new engine will use the 95cc heads but my pistons are what will get me into the 9.5:1 neighborhood that I am after.