One for the Rat Motor Guys

[William C.]

The original design of the 396 and 427 engines (65-66 for sure) di not use locating dowels in the timing cover to provide alignmnet, and there were no holes in that area of the timing covers ffor early engines. What year were the dowels added, 67, 68, or '69?

[Wayne M.]

Dowel Pins began w/block 3935439

From A. Colvin's book. This block used late 1968 model year in Corvette and Passenger cars. Also early 1969 MY.

[Mark #28455]

approx April 1968

I have an original March 1968 cast 439 block for a 400 HP motor with the cast bosses for the dowels but was never drilled, I also have several May 1968 cast blocks, both 2 and 4 bolt main, all are drilled for the dowels.

Hope this helps,
Mark