1968 L79 pulleys and belt configurations. I understand

[Jeff P.]

Joe I was going to wait a while but I saw you chimed in on a pulley thread recently. I've looked at past archives and the AIM. I've never got a definitive answer or found for that matter the correct pulleys for a 68 L79 with A/C and Power Steering. This is a HP motor. I understand the crank and water pump have a dual pulley. Mine aren't what I've seen in past threads. I do have an add on pulley on the water pump. At your convenience could I have the correct pulley numbers for my application.i believe the only pulley that was correct so far was my smog pump.thank you as always Jeff

[Joe L.]

Re: 1968 L79 pulleys and belt configurations. I understand

Joe I was going to wait a while but I saw you chimed in on a pulley thread recently. I've looked at past archives and the AIM. I've never got a definitive answer or found for that matter the correct pulleys for a 68 L79 with A/C and Power Steering. This is a HP motor. I understand the crank and water pump have a dual pulley. Mine aren't what I've seen in past threads. I do have an add on pulley on the water pump. At your convenience could I have the correct pulley numbers for my application.i believe the only pulley that was correct so far was my smog pump.thank you as always Jeff

Jeff------


Basically, the 1968 L-79 with N-40 and C-60 pulley set-up is the same as 300 HP with N-40 and C-60 although there are a few differences.

waterpump, rear, 2 groove-------------------------GM #3890419

waterpump, front, 1 groove (AIR driver)-----------GM #3883234

crankshaft, rear, 2 groove -------------------------GM #3850838

crankshaft, front, 1 groove (p/s driver)------------GM #3751232

power steering pump-------------------------------GM #3770509

AIR pump--------------------------------------------GM #3917234

Alternator (pulley with integral fan)-----------------GM #3909817

[Jeff P.]

Re: 1968 L79 pulleys and belt configurations. I understand

Thank you Joe for your time.

[Jeff P.]

Re: 1968 L79 pulleys and belt configurations. I understand

Joe the crankshaft pulley that was on there was 3911013. What was the application for this pulley?

[Joe L.]

Re: 1968 L79 pulleys and belt configurations. I understand

Joe the crankshaft pulley that was on there was 3911013. What was the application for this pulley?

Jeff-------


The 3911013 was used for most 1968-74 small blocks with C-60. However, my information indicates that the 1968 L-79 was an exception. The 3850838 and 3911013 are very similar pulleys with the 3911013 being a little larger in OD.

[Joe L.]

Re: 1968 L79 pulleys and belt configurations. I understand

Joe the crankshaft pulley that was on there was 3911013. What was the application for this pulley?

Jeff------


By the way, does your 3911013 have a 3751232 sandwiched onto the front of it?

[Jeff P.]

Re: 1968 L79 pulleys and belt configurations. I understand

Joe, the diameter of pulley 3911013 is 7 11/16. The diameter of pulley 3751232 is 6 3/4. They don't look like they could be sandwiched together. This car is original A/C but I'm adding the PS. Looks like when C60 is added the pullieys you mentioned are used. The water pump pulley is 3876846 with a diameter of 6 3/16. Add on pulley is 3883235 with diameter of 5 15/16. As always very interesting.

[Joe L.]

Re: 1968 L79 pulleys and belt configurations. I understand

Joe, the diameter of pulley 3911013 is 7 11/16. The diameter of pulley 3751232 is 6 3/4. They don't look like they could be sandwiched together. This car is original A/C but I'm adding the PS. Looks like when C60 is added the pullieys you mentioned are used. The water pump pulley is 3876846 with a diameter of 6 3/16. Add on pulley is 3883235 with diameter of 5 15/16. As always very interesting.

Jeff------


Yes, the pulleys you mentioned are the correct ones for the application with C-60 but without N-40.

The fact that the 3911013 and 3751232 are different OD's should not, by itself, affect whether the 2 will nest together. As a matter of fact, the GM #3850838 is a considerably different OD than the 3751232 but those two pulleys will nest together perfectly. I have NOS examples of both the 3911013 and 3751232 but I'm too sore and lazy to go dig them out and see if they'll nest.

[Jeff P.]

Re: 1968 L79 pulleys and belt configurations. I understand

You stay put Joe. I took a couple pictures of the 3911013 with the 3751232. Your the authority but they don't match up well. Could be me though. image.jpgimage.jpgimage.jpg

[Joe L.]

Re: 1968 L79 pulleys and belt configurations. I understand

You stay put Joe. I took a couple pictures of the 3911013 with the 3751232. Your the authority but they don't match up well. Could be me though. [ATTACH=CONFIG]59687[/ATTACH][ATTACH=CONFIG]59688[/ATTACH][ATTACH=CONFIG]59689[/ATTACH]

Jeff------


In your third photo it looks like you might have the pulleys "back-to-back" although I can't really see the 3911013 too well in that photo..

[Jeff P.]

Re: 1968 L79 pulleys and belt configurations. I understand

Well, I remember you saying the single goes in front. So I didn't know any other way they would fit. LOL

[Joe L.]

Re: 1968 L79 pulleys and belt configurations. I understand

Well, I remember you saying the single goes in front. So I didn't know any other way they would fit. LOL

Jeff------


The single groove does go in front. However, it fits into the front (dished) of the 2 groove pulley.