Portagee
Well-Known Member
I'm building a 440 for my '69 bee, and have just finished assembling the short block. For reference, I'm using a '74 block (std bore) with a standard forged crank, six pack rods, and stock flat top pistons.
I just measured the deck clearance to be 0.150", and a calculated CR of 7.8:1 (using 0.039 gasket and 906 heads, estimating 86cc chambers).
I read that this is typical for smog engines with low compression, but definitely not what I'm looking for with this engine. I plan to run comp cams' version of the MP purple cam (K21-672-4), so this compression ratio is not gonna cut it.
Any recommendations on how to address this? I've considered everything from decking the block, milling the heads, using a shim head gasket, etc...
I'm thinking that the best path forward would be a piston swap, but I don't know how to select the best aftermarket piston for this application.
Thoughts?
Thanks,
Mike
I just measured the deck clearance to be 0.150", and a calculated CR of 7.8:1 (using 0.039 gasket and 906 heads, estimating 86cc chambers).
I read that this is typical for smog engines with low compression, but definitely not what I'm looking for with this engine. I plan to run comp cams' version of the MP purple cam (K21-672-4), so this compression ratio is not gonna cut it.
Any recommendations on how to address this? I've considered everything from decking the block, milling the heads, using a shim head gasket, etc...
I'm thinking that the best path forward would be a piston swap, but I don't know how to select the best aftermarket piston for this application.
Thoughts?
Thanks,
Mike