C2 Valvetrain

[Justin N.]

Dear Members,
I managed to find the correct #462 heads for my 67 327 from a wrecking yard. I now need to rebuild these heads. The machine shop has already installed the LT1 cam in shortblock. What part # headsprings should I use for this cam? Does GM still have these available? Thank you much!

Justin #41362

[Duke W.]

Re: C2 Valvetrain

The LT-1 cam, as did all other SHP mechanical lifter cams, used the same valve spring as all other small blocks of the same era. The seventies vintage valve spring is 3911068. This spring went into regular production in '67, replacing the 3735381. The original LT-1 engines have screw in studs and pushrod guideplates along with the companion hardened pushrods, but I do not consider these mandatory when installing the LT-1 cam in an earlier engine. Also, since the LT-1 cam has soft action it should not pull pressed in studs.

The 068 has slightly higher preload and rate, and I beleive it eventually replaced the 381 for service.

If GM no longer offers the 068, it should be available on the aftermarket. Just order OE replacement springs for a '67-up SB without exhaust valve rotators.

Duke

[Joe L.]

Re: C2 Valvetrain

Duke and Justin-----

The GM #3911068 valve spring is still available and that's the one that I would recommend for the application. It will fit in most 327 cylinder head valve spring pockets with no modification, at all. The GM #3735381 spring is still available, too, but I wouldn't use it.