Engine Block Numbers

[Tom Northcott]

About two years ago I purchased a 1971 roadster with what I thought to be a 1968 Corvette 427 Tri-Power in it. Originally the car was a LS-5. After sending the engine off for rebuilding, I discovered the intake is from a 68 or 69 with the number 3937797 cast in it, but my block and heads are confusing me. I hope someone can shed some light on this subject.

My block numbers are 3869942 which I believe is the code for a 67 or 66 427, but the front of the block is marked T06I0IP. I have no idea what this code is.

My Heads are even more perplexing to me. The have Hi-Perf cast in them and the numbers are 3964291. In the NCRS book it shows these heads to be from a 1970 LS7 with 460 HP which was not for retail sale. Is it possilbe these heads were experimental? The car did come from St. Louis where it was built.

If some one could help me I would appreciate it.

[Joe L.]

Re: Engine Block Numbers

Tom----

Your engine block was originally installed in a 1966 Corvette with special high performance 427(L-72). The block casting number and engine "IP" suffix code confirm that.

Your 3964291 cylinder heads are rectangular port, hi performance cylinder heads originally used on all 1969 Chevrolet cars equipped with special hi performance, solid lifter 396 and 427 engines. They were also used in 1970 for 402 and 454(LS-6) engines with special high performance and solid lifters installed in Chevelles, Novas and Camaros.

[Joe L.]

Re: Engine Block Numbers

Tom----

Your engine block was originally installed in a 1966 Corvette with special high performance 427(L-72). The block casting number and engine "IP" suffix code confirm that.

Your 3964291 cylinder heads are rectangular port, hi performance cylinder heads originally used on all 1969 Chevrolet cars equipped with special hi performance, solid lifter 396 and 427 engines. They were also used in 1970 for 402 and 454(LS-6) engines with special high performance and solid lifters installed in Chevelles, Novas and Camaros.