cutlassefi

Fwiw - here's the sheet showing the wall thickness on a DX block I just had done.
Based on these numbers not sure I'd go much past 4.155. The areas that are around .150 thick would be the problem.

Hope this helps.

cv5800

Do you know if there are any differences in strength or any other advantages between the D and DX blocks? I just picked up a D block and plan on building a street motor.

chadman

What bore was it at when checked?

cutlassefi

Stock, 4.057.
From my experience there's no real wall thickness difference in a D or DX. It's hit or miss imo. But D block uses the .842 lifter, the DX uses the .921.