1972 440 steel crank

[Nix777]

I’ve got a 1972 440 steel crank motor I’m almost positive is stock. Anyone know what the stock compression is? I’m trying to decide what way to go with this build.

 

[Curiousyellow71]

1972 440 has a 8.2:1 low compression piston if its original.
Likely could even be in the 7's. Same piston was used in lots of 440s 72-78.
If the engine is in good shape you can replace them with a higher compression oem piston. The pistons were identical as far as where the rings are, the top of the piston is just taller on the 67-71.

 

[GTX JOHN]

The 72 up about an 1/8 inch down in the hole.
You need a flashlight to see them. about a hundred thou
lower than 68/69 pistons.

NHRA spec is round 8 to 1 compression while there spec is
about 10 to one on 68/69s. That is if everything is blueprinted
to minimum perfect specs.

Big difference in performance:

My 69 charger showroom stock ran 14.1 in 1/4 @ 99
My 73 Charger ran 15.2 @ 92
Both when Brand New.