Block

By Jeff Finley

The heart of it all. The block. Casting numbers on BOSS 302 blocks should be C8FE-6015-B for 1969. We have heard of C8FE-6015-B used on very few early 1970's. We have heard of D0ZE-6015-A used for a few late 1969's. D0ZE-6015-B or C for most of 1970. Ford did make ONE prototype 1971 BOSS 302 Mustang and then the 1971 program was canceled.

The C8FE-B Tunnel Port blocks were utilized as service replacement blocks in 1969. The D0ZE-A, D0ZE-B and the D0ZE-C were used for service as well depending on when the replacement took place. Finally the D1ZE tooling was already cut so D1ZE-6015-B was used for service blocks.

Model Year	From the Factory	Service
1969	C8FE-6015-B	C8FE-6015-B
late 1969	C8FE-6015-B D0ZE-6015-A	C8FE-6015-B D0ZE-6015-A
early 1970	C8FE-6015-B D0ZE-6015-A	D0ZE-6015-A D0ZE-6015-B D0ZE-6015-C
1970 remainder	D0ZE-6015-B D0ZE-6015-C	D0ZE-6015-B D0ZE-6015-C
thereafter		D0ZE-6015-C D1ZE-6015-B

If you are looking to replace a block and numbers matter to you then the key is to look at the part number and the date code on the block. Use a block that is date coded before the build date of your car. We frown on V.I.N. stamping a replacement block and it just might be illegal.

Note the BOSS 302 block features in the photos below. Four-bolt main bearing caps, screw-in freeze plugs. Also note the location of the casting numbers hidden by the starter when completely assembled.

Casting (part) number on top and date code underneath