Sorting out early big block valve springs

[Clem Z.]

the L-88 springs are designed for .600 lift

where the LS-6 spring is only good for .500 so the spring is designed differently

[Joe L.]

Re: Sorting out early big block valve springs

Duke-----

I strongly recommend using the GM #3970627 "valve spring" on the 1966 L-72 engine. Actually, the 3970627 is a valve spring KIT. With every one of these I have ever purchased, it includes the valve spring (inner and outer) + retainer with integral "umbrella-type" oil seal. A complete engine set of the GM #3970627 "valve springs" is available under GM #12371061. However, I do not know if the engine set includes the retainer/oil shield components. I expect that it does, but I do not know that for a fact. IF you do need to order the retainers separately, order GM #3964264. These retainers definitely include the oil shield.

The GM #3970627 "vale springs" are tried-and-true. After "blowing it" with the 65-69 springs, GM got it right with the 3970627. For a street engine, these are hard to beat.

The 12371061 kit costs about $225, discount priced. I would use it rather than any other "equivalent" (which may or may not be actually equivalent).