1969 corvette 427 motor casting number 3955270

[william 38271]

This casting number (3955270) used for a 400 horse 1969 corvette should be a 2 bolt main version, in my opinion, and that of my peers. An individual interested in this motor for his october 1969 400 horse car says that the book "Chevrolet by the Numbers" says 400, 430, and 435's are 4 bolt main blocks. I agree the 430's and 435's are 4 bolt. However, the 400 should be a two bolt. Would someone please tell me who is correct and if there is a place I can find this in writing, such as a judging manual, for instance. The date code is H26-8, 5 weeks before his build date. T0903LM 390 horse block which should be the same, other than the code, as a 400 block. The main question is--should a 400 horse block be a two bolt main.

[Dick W.]

Re: 1969 corvette 427 motor casting number 3955270

The generally accepted norm is that the 400 is a two bolt block. There have been reported blocks for the 390 and 400 being four bolts, but this is the exception rather than the norm

[Don W.]

Re: 1969 corvette 427 motor casting number 3955270

The 1969 400hp engine is the base 427/390 HP, 10.25:1; 2-bolt main engine, same non high performance heads, with 3 X 2-barrel carbs and the associated low rise aluminum intake manfold added

Don

[Kevin Cavanaugh]

Re: 1969 corvette 427 motor casting number 3955270

Here's a little more info on the 3955270 blocks. I have three of the 270 blocks; one was cast very late in August, 1968 and the other two are September 8th and 25th of 1968. The 270 block cast on Sept 25th is a 2 bolt block and is for ser # 5956 which is a 427/390 LM suffix engine. The other two are 4 bolt blocks and are for ser #'s 12,636 and 13,099. Ser# 12,636 was assembled on Nov. 25,1968 and ser# 13,099 was assembled the following day, Nov.26,1968. Both of these are 4spd 435/L89 engines. Hope this helps a little.