1969 Big Block Pulleys

[Dennis W.]

I have 2005 ZZ502 Gen VI engine I'm putting in a 1969 Coupe. The pulleys from the 427 or later model with 454 should work. Can someone help me find the correct part numbers used for the crank, water pump, P.S., alternator, and AC. No AIR. My Assembly Manual is vague on the pulleys and belts. Belt info would be great as well. I have purchased some pulleys from Corvette Central and Ecklers but the water pump is really causing me problems.I think this one may need some shims. Any help would be great. Thanks. Dennis 39883

[Ridge K.]

Re: 1969 Big Block Pulleys

I have 2005 ZZ502 Gen VI engine I'm putting in a 1969 Coupe. The pulleys from the 427 or later model with 454 should work. Can someone help me find the correct part numbers used for the crank, water pump, P.S., alternator, and AC. No AIR. My Assembly Manual is vague on the pulleys and belts. Belt info would be great as well. I have purchased some pulleys from Corvette Central and Ecklers but the water pump is really causing me problems.I think this one may need some shims. Any help would be great. Thanks. Dennis 39883

Dennis, I can't help you with the fan belt info, or the crank, power steering, alternator or AC, but I can tell you about the correct 1969 427 water pump pulley.
The original was GM part number 3889372, and is a three groove pulley. The part number on originals should be stamped on the front face (hub area), and they are "pricey". In my former parts dealing days, originals brought $200 to $250, or higher.
The service replacement water pump pulleys were GM part number 3995644. I believe that both have long been discontinued. (p.s. there is a 3889372 listed on eBay right now) (I am not connected to the seller at all).
This water pump pulley is currently reproduced, but I have been told that it is manufactured in aluminum as a repo, and the originals were steel.
Maybe this info will get you started in the right direction. Hopefully, one of the many C3 experts will step in, and, the archives will probably have a lot of good info also.
Good luck, Ridge.

[Joe L.]

Re: 1969 Big Block Pulleys

I have 2005 ZZ502 Gen VI engine I'm putting in a 1969 Coupe. The pulleys from the 427 or later model with 454 should work. Can someone help me find the correct part numbers used for the crank, water pump, P.S., alternator, and AC. No AIR. My Assembly Manual is vague on the pulleys and belts. Belt info would be great as well. I have purchased some pulleys from Corvette Central and Ecklers but the water pump is really causing me problems.I think this one may need some shims. Any help would be great. Thanks. Dennis 39883

Dennis-----

crank----GM #3863108 OR GM #3921923 (either will work)

waterpump----GM #3889372 OR GM #3995644 (either will work)

power steering pump pulley----GM #3878245

alternator-----3883978

A/C-----GM #6550750

Except for the 3921923 and GM #3863108 crank pullies, ALL of the above are GM-discontinued. The 3863108 is available through the GM parts system as a GM reproduction part, though.

Also, for the above to work you MUST use a SHORT waterpump. No Corvette, big block or small block, ever used a 69+ "long" style waterpump.

[Dennis W.]

Re: 1969 Big Block Pulleys

Was there an idler pulley on these engines?

[Dennis W.]

Re: 1969 Big Block Pulleys

Thanks for the info. Was there an idler pulley on these engines?

[Joe L.]

Re: 1969 Big Block Pulleys

Thanks for the info. Was there an idler pulley on these engines?

Dennis-----


Yes, an idler pulley was used for 68-74 Corvettes with big block and C-60. For 1969 the assembly was GM #3952332. It's long-since GM-discontinued but available in reproduction.

[Rob M.]

Re: 1969 Big Block Pulleys

Depends what options you had on your car. Mine hasn't got AIR but has power steering and does have an idler pulley (rear groove).

regards,
Rob.

[Joe L.]

Re: 1969 Big Block Pulleys

Depends what options you had on your car. Mine hasn't got AIR but has power steering and does have an idler pulley (rear groove).

regards,
Rob.

Rob------


AIR was not an option for 1969. It was supplied on all cars. As far as the idler pulley goes, the triggering factors were C-60 and L-36 or L-68. If the car had those, it got the idler pulley regardless of other options or lack thereof.

[Erik S.]

Re: 1969 Big Block Pulleys

Joe - does this mean that L71 does not necessarily have such a pully?

[Joe L.]

Re: 1969 Big Block Pulleys

Joe - does this mean that L71 does not necessarily have such a pully?

Erik-----


The L-71 was not available with C-60. So, with no C-60 one of the two "triggering" requirements could not be met. Therefore, no L-71 was equipped with the idler pulley assembly.

[Jeff G.]

Re: 1969 Big Block Pulleys

FYI - In lieu of an idler pulley, the 69 configuration used a tensioner on the water pump belt for the C60. The 69 AIM is wrong, I think the config. diagram was a carry over from 68.

[Joe L.]

Re: 1969 Big Block Pulleys

FYI - In lieu of an idler pulley, the 69 configuration used a tensioner on the water pump belt for the C60. The 69 AIM is wrong, I think the config. diagram was a carry over from 68.

Jeff-----


The 1968 model year piece was much different than the 69-74 which is more of a tensioner than a pulley. However, GM referred to both as a BELT IDLER PULLEY.