67 427 PS water pump pulley no AC

[John M.]

I have spent a lot of time trying to find one of these P/N 3906656. There is one on eBay that can be had for $175. I just took the exact same pulley that had no part number on it off of my 69 BB driver. Does anybody know where I can get a repro of this pulley with or without the number, or is there another P/N or service part that is nearly the same?
Thanks,
John McRae 30025

[Rob A.]

Re: 67 427 PS water pump pulley no AC

Make sure you check on ebay under parts and accessories without selecting the corvette category. You'll find it for much less when it's listed elsewhere, which they often are. $175 is definately steep! Paragon has the 2 groove pulley for around $127, less 10% discount if you tell them you're an ncrs member when you order.

[John M.]

Re: 67 427 PS water pump pulley no AC

Thanks Rob,
I've had this thing on order with Paragon since last May. Goat Hill is supposed to be making it for them but it keeps getting delayed another month, another month, for 8 months now. I want to get this car going so I stold the one off the other car, but still need one. Is your 67 running now? Been watching your progress.
John

[Rob A.]

Re: 67 427 PS water pump pulley no AC

John,

I'm finally done. It came out very nice and the engine runs smooth, so I guess I've learned that I shouldn't be surprised at all the little problems that occurr just when you think you're done. I've seen these pulleys on ebay for around $60-$80 recently. I found mine for around that, under the pulley category in collector parts and accessories. If I see one, I'll email you.

Rob

[John M.]

Re: 67 427 PS water pump pulley no AC

Thanks Rob, Good luck with the car, it sounds like a beauty. You should post a couple of pictures.

[Joe L.]

Re: 67 427 PS water pump pulley no AC

John-----

The GM #3906656 pulley was discontinued without supercession. I would think that the pulley used for early 1968 w/427 (and other applications) would work, at least as far as belt alignment is concerned. This pulley is still available under GM #3995641. However, the problem is that the 3906656 was 7-3/16" OD and the 3995641 is only 5-7/8" OD. So, the drive speed of the fan will be changed. 1966-67 big blocks are the only ones that used such a large waterpump pulley. After 1968 the w/p pullies for most Corvette big block applications were considerably smaller.

[John M.]

Re: 67 427 PS water pump pulley no AC

Joe,
This is interesting because I just took the water pump pulley off of my 69 BB, with short pump and it is double groove 7 1/8-3/16 diameter, wrong for the application, with no number on it, but the right size for the 67. So I should get the 68 pulley and a new belt for the 69 and all will be well? (I hope)
Thanks guys,
John

[Joe L.]

Re: 67 427 PS water pump pulley no AC

John------

The early 68 BB 2 groove pulley is used in conjunction with a 1 groove pulley, GM #3883235. The latter pulley drives the A.I.R. pump. It is GM-discontinued but available in reproduction. The later 1968 through 1970 big block pulley was a 3 groove pulley. 1968-69 L-88/ZL-1 used the same 2 sandwiched pulley set-up as early 1968.