MarkEstes

I'm considering purchasing a block for my 66 390 hp 427. It has casting # 3855961 and dated 5/23/66. Is this number correct for my 66 390 hp?
Engine ID has been milled off. :cheers: Mark

67435animal

My book says that this block casting number was used in early Corvettes, not late Corvettes. A date of May 23, 1966 is a late production date so my guess is that this engine did not come out of a Corvette. Assuming your car is a late car, the block casting number you would want is 3869942.

I'm sure that others will have differing opinions; I am only stating what is in front of me in the NCRS Pocket Guide.

GRTaylor

:iagree: My Cars & Parts catalog of Chevy V-8 Casting numbers says casting #3855961 was used in 65-67 passenger cars as a 396CI 325 HP engine with 2 bolt mains. It was also used in the 66 Chevelle and 68-69 light truck configured as a 396. The book also says it was used in the 66 Vette in both 390 & 425 HP versions with 2 and 4 bolt mains. The C&P catalog also lists the casting #3869942 as being used in the 66 Vette and passenger cars configured as 390 or 425HP-427CI. I agree that the #3869942 is the correct block for a late 66 Vette. Just my .02. :) Anyway, you can't argue with the NCRS pocket guide. Those guys did a bunch of research work. :lol:

provette67

67 435 animal is correct,you need a 942block(last 3 casting numbers)961 was used in the passenger cars