1965 396 block casting #3855961??

[Robert M.]

Today I looked at an original 65 L78 cpe with documentation back to new. The car appears to be a survivor. I believe the vin# is 15736. It has a 3855961 block! Along with the documentation is a letter from a respected corvette expert attesting to what appears to be an original engine using the thinner walled,two bolt "961". Was this block ever used in a corvette? It appears to have the early design radiator #3005936. Alternator and carb appear original,as do most other components.

[William C.]

Re: 1965 396 block casting #3855961??

Documented use of two bolt configuration in a Corvette has not been seen. The four-bolt block was part of the 425hp package. Are you sure it is a two bolt?

[Robert M.]

Re: 1965 396 block casting #3855961??

Bill,Maybe I was seeing things. I won't be able to get back and see the car for a week,but I will look again and take some pictures. I know the "961" was used in 66 for 390 and 425hp applications.

[Joe L.]

Re: 1965 396 block casting #3855961??

Rob-----

In 2 bolt main configuration, I don't think that this block would have been used in a Corvette. However, the '961' block casting can be finished into a 4 bolt main block just as easily as a '962' casting can be. So, I would not be surprised, at all, if some early 1965 Corvette L-78s were built using the '961' casting. It seems to me that I have heard of this before, too.

[Joe L.]

Re: 1965 396 block casting #3855961??

Rob-----

Some sources may indicate that the 3855961 block was used for 1966 427 applications. However, I'd have to see one before I'd believe it. The GM #3855961 casting was 396 block. I don't see how it could have been used for the larger bore, 427 application.

[Clem Z.]

Re: 1965 396 block casting #3855961??

i build 2 427s from the 1965 396 corvette blocks,i knew nothing about block numbers back them we just built them. lots if cast iron chips. this is the only 396 block that can be bored to 4.250". i think chevy was going to build a 427 in 65 but GM made them keep it under 400 cu in. i tried a camaro 396 block but all 8 cylinders cracked the first time we ran it.

[Robert M.]

Re: 1965 396 block casting #3855961??

I will see this car again in a week and take a much closer look.

[Robert M.]

Re: 1965 396 block casting #3855961??

Joe, Where was the 961 blocked used? Chevelle? Impala?

[Clem Z.]

Re: 1965 396 block casting #3855961??

mortec says BBC 961 65-66 396 2-4 bolt,66 427 2 bolt.

[Joe L.]

Re: 1965 396 block casting #3855961??

Rob------

It was used for 396 cid 325hp engines in 1965 passenger cars and 396 cid 325 and 360 hp engines in 1965-66 Chevelles.

[Joe L.]

Re: 1965 396 block casting #3855961??

clem-----

Yes, the '962' cylinder block (i.e. the casting normally used for 1965 L-78) had substantially thicker cylinder walls than other 396 blocks, including the '961'. However, it's the '961' that some references say was used for early 1966 427 applications.

[William C.]

Re: 1965 396 block casting #3855961??

All two-bolt configurations it should be noted. Used to crack the walls on these all the time with my SS/I car in the early 70's. (060 oversize bore)

[Gary Chesnut]

Re: 1965 396 block casting #3855961??

Looked at a Blue '65 Coupe "survivor" type Corvette with 2 bolt block several years back for Al Grenning. Couldn't find my info - suggest you check with Al. Gary#5895....

[Hal J.]

Re: 1965 396 block casting #3855961??

Not sure if this is validation. Page 352 Noland Adams Complete guide Vol 2 Revised (mine is copywrite 1988) lists two L36 cars #194676S100828 and # 194376S104092 with block 3855961.