"3970016" That's the part # for an over the counter block that he felt was the best at the time.Bob Hollinshead wrote: ↑Sat Feb 16, 2013 11:19 am From Jenkin's book The Chevrolet Racing Engine: page 8, for racing use it is valuable to select a block that is "hard". There is some variation in the production casting material, and we often use a portable Brinell tester to find "hard" blocks. Page 6. The best factory block casting to obtain is part number 3970016. This case has the thick main webs and 4-bolt caps for added crankshaft support.
Does anyone know if this block was used in production vehicles also? If so, do you know the casting number on this block?
Thanks.
Dave