tore down the top end....here's what i found

[green67cuda]

well.......i got the engine all cleaned up and started stripping down the top end tonight....
it doesn't look like the block deck has been milled, and the pistons are .9-ish down in the hole (all i have to check it with is a dial indicator...i set it up on the flat deck surface, zeroed it, then put it so the indicator was on the center of the piston at TDC.....

has flattop pistons

bores measure in at 4.34, so it's a standard bore

now the heads........
they have milling marks on them (arced lines across the head), but the measurement to the center of the flat spot in the chambers, measured the same as the block, turn out to be .075-.080.....and i have no idea what that means as far as chamber cc.....also, the tops of the casting numbers on the bottom side are milled down....the milling is about flat with where the very tops of the numbers are...so that's another indication that they HAVE been mille....i just have no idea how much

it all kinda sucks because that means i don't have much more than the stock 8:1....but at least i know what i have and will find out closer to what the CR really is....

 

[green67cuda]

wonder if i should go ahead and take the heads to have them milled more..................

 

[AdamR]

Have them CCd first.

 

[turbodart]

yes, definetaly cc the heads first. that is an important part of the equation. like you said, you probably have 8 to 1 at best. the best i ever found on a bone stock 400 was 7.9 to 1. the only choice here is a piston swap, milling the heads more could induce a number of other problems (intake fit, pushrod/rocker geometry, etc ). keith black now makes a set of flattops for a 400 motor, i think they are #240. with minimal deck milling, you can make it a zero deck motor and have a good 9.5 to one engine.

--chad