Hi!

Im rebuilding a 440 engine and I called summit and they are out of 30 over 440 pistons with a low street and pumop gas friendly compression ratio.

all they have is this:

http://www.summitracing.com/parts/UEM-KB822-030/

Do you think I can machine a small dish on these pistons to lower the compression ratio a bit or would it be asking for trouble???

No
Besides when your done with them, the cost of machine work in the cheap-o- Forger pistons, you could have a set of Diamond Customs for the same money..
IMO
your better off just looking at a set of Speed Pro pistons..
Look
http://www.jegs.com/p/Sealed-Power/Speed-Pro-Powerforged-Chrysler-Pistons/755704/10002/-1

Why not use the head gasket thickness to kill C/R?

I went ahead an bought the pistons....summit was out of stock on the TRW or speed pro forged slucgs in 9:1

So I bought those which will get me to around 10:1 with cast iron heads.

I bought one of those cheap fel pro gasket kits too. Whats the head gasket thickness on those???

If I could get a thicker head gasket which one would it be? I know Cometic will make you one in any thickness you want, but I hear they are PRICEY.

Do you think I will be runngin into trouble with 10:1 and pump gas with iron heads? I also went with this cam http://store.440source.com/Comp-Cam-Xtreme-Energy-507_510/productinfo/145-1225/

How is the gas quality your going to be using in that motor,octane rating, leaded or unleaded, ethanol or no ethanol?

It's been a couple months but I believe Felpro's sandwich are .042 thick.

actually, with 906 heads, most unmilled run ~92 cc. those pistons at 0 deck, with a .04" head gasket will net you 9.55:1 compression.

blueprint 440 specs are deck height: 10.725, rod length 6.768". with those pistons compression height, they'll be .015 in the hole if everything is to blueprint. with 92cc heads, and .040 head gaskets, that puts you at 9.27:1 compression.

to get 10:1 compression with those pistons, they need to be .005-.010" in the hole with 84cc heads, and a .040 head gasket

Felpro .037,.040 and .051,Cometics is way cheaper than machining pistons or buying new ones.