[Jack21]

The D2 was a '72 block.

The '68 (C8), and '69 (C9) blocks were pretty beefy, but the block deck heights were 2/10" shorter. Aftermarket pistons will need to be skinned up to 2/10" to get Zero deck height. '70 up are all the same.

For a street motor, any '70 - up block will work, but using a '70 - '74 block 1) may be a little beefier, 2) will give you an over 25 year old motor for registration (Classic/Antique vehicle) and (non) required emissions testing purposes.

For a stroker, ask your machinist about installing aftermarket 4 bolt center main caps for additional bottom end strength. And, of course, ARP hardware on mains, and rods. (With 180,000 pounds tensile strength, one main bolt will lift an entire trailerload of Cobras, including the trailer, and not break.)