Looking for clarification on a 396 Block.
04-12-2006, 01:57 PM
#1
Team Owner
Thread Starter
Looking for clarification on a 396 Block.
Looking for some clarification on a 396 engine I’m looking to buy. I went out to Mortec and cross the number and it shows 3855961 being used in 65-66 as a 396 and as a 427 in 66.
Chevrolet by the Numbers states that the 427 used in 66-69 is a bored out 396. I’m thinking of installing this 396 in my 65 project. It is a 2-bolt main block with 206 Oval port heads 97cc but I should be able to get some good HP out of this setup.
Question is: Did GM bore the 3855961 block from 396ci to 427ci? That would have been a .157 cut.
Chevrolet by the Numbers states that the 427 used in 66-69 is a bored out 396. I’m thinking of installing this 396 in my 65 project. It is a 2-bolt main block with 206 Oval port heads 97cc but I should be able to get some good HP out of this setup.
Question is: Did GM bore the 3855961 block from 396ci to 427ci? That would have been a .157 cut.
04-12-2006, 04:12 PM
#2
Le Mans Master
The 427 came first; so GM probably added metal to get below 400 cubes. Per GM mandate that all cars not full size have no more than 400CI.
The 396 didn't come out till may of 65 ( I think I saw that somewhere ); and in 66 the 427 was put in vettes. That was not very long to develop many blocks. So Chevrolet by the Numbers is right but not really. The way I look at it is the 396 is an under bored 427.
The racers took the 396 and bored it as far as they could; So I would say that GM made some of the 961 blocks with thick walls so they would be able to bore them to 427.
The 396 didn't come out till may of 65 ( I think I saw that somewhere ); and in 66 the 427 was put in vettes. That was not very long to develop many blocks. So Chevrolet by the Numbers is right but not really. The way I look at it is the 396 is an under bored 427.
The racers took the 396 and bored it as far as they could; So I would say that GM made some of the 961 blocks with thick walls so they would be able to bore them to 427.
04-12-2006, 04:30 PM
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Originally Posted by r quicke
I think the correct casting for a 65 396 should be a 3855962 4 bolt main.
04-12-2006, 04:51 PM
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Originally Posted by Mr D.
Looking for some clarification on a 396 engine I’m looking to buy. I went out to Mortec and cross the number and it shows 3855961 being used in 65-66 as a 396 and as a 427 in 66.
Chevrolet by the Numbers states that the 427 used in 66-69 is a bored out 396. I’m thinking of installing this 396 in my 65 project. It is a 2-bolt main block with 206 Oval port heads 97cc but I should be able to get some good HP out of this setup.
Question is: Did GM bore the 3855961 block from 396ci to 427ci? That would have been a .157 cut.
Chevrolet by the Numbers states that the 427 used in 66-69 is a bored out 396. I’m thinking of installing this 396 in my 65 project. It is a 2-bolt main block with 206 Oval port heads 97cc but I should be able to get some good HP out of this setup.
Question is: Did GM bore the 3855961 block from 396ci to 427ci? That would have been a .157 cut.
these 396 corvette blocks are casting # 3855962 and the suffix "IF"
