67 427 PS water pump pulley no AC

[John M.]

I haven't been able to locate this pulley. It's been on back-order for over 6 months from the normal parts guys. Can a 68-69 or other be substituted?
Thanks for any ideas.

[Joe L.]

Re: 67 427 PS water pump pulley no AC

John-----

The 1966-67 big block waterpump pulley, GM #3906656, is now GM-discontinued. That's probably why it's "back-ordered". The GM supply is dry and someone's waiting for a reproduction to become available. Your in the "betwixt and between" period.

The 68-70 big block waterpump pulley is also discontinued, but it's been discontinued long enough for a reproduction to be available. The problem is that it's a 3 groove pulley and of considereably smaller diameter than the 3906656. The 3906656 is 7-1/8" OD and the 3889372 (original L68-69) is 5-1/2" OD. As far as pulley alignment goes, I THINK that it MIGHT work, though. It's expensive so it would be an expensive "experiment". Plus, it's nowhere near correct.

One other thing that might work in a pinch is the GM #3995641. This pulley is a 2 groove pulley that was used mostly for small block applications. However, its forerunner was originally used for early 1968 427 applications. This pulley is smaller in OD than the 3906656 with an OD of 5-7/8". However, I THINK that the pulley alignment will be ok. DRIVE SPEED will be affected, though. The GM #3995641 is still available from GM for a current list price of $58.69. NO GUARANTEES, though, that it will work, for sure.

[Rob A.]

Re: 67 427 PS water pump pulley no AC

Now that you have the # of the pulley, check ebay. I've seen them there occasionally (Look under more than just the corvette section of parts)