1972 C10 balancer & pulley problems

[rustytruck50]

Hopefully this isn't as difficult as it feels, but here goes headscratch
The truck in question is a '72 Custom Deluxe 10, 350, auto, ps,ac. I've owned it for almost 2 years, driving it pretty much daily. The engine is original to the truck, verified by the pad on the block. Sometime in the truck's past, it was converted to HEI, but the distributor was not put in right (#1 not in right position on distributor). The intake was leaking pretty good, so I thought it would be a good time to fix both things.

I will admit, I didn't take note of how the distributor came out only because it wasn't put in right to begin with. When I found TDC, I lined up the balancer on zero on the timing tab, set the distributor in place with one on the rotor pointing at the #1 cylinder. When I grabbed the timing light and tried to set the timing, the mark was nowhere to be found, kinda. computer_punch John & I were pretty confused about this & just for fun, I shined the light from below and found the timing mark at about the 4-5 o-clock position. My first thought was to do some reading on line and the general thought was the outer ring slipped, causing the problem with timing.

I bought a replacement from O'reilly, pn PB1046N. I compared it to the one I took off abd the size was the same, but the mark was in a different location, about 2" away. Once I went to put the crank pulley on, the ps, wp and ac pulleys no longer line up. I tried spacing the crank pulley, but that corrected the ps alignment, but nothing else. Next, tried to space out the alternator bracket only to find it not right either. If you're still on board, thank you!!!

Confused and frustrated, I checked the number on the back of the old balancer, 6272222. I Googled this and not surprisingly found that it wasn't right for my truck, fits almost everything else. Need to note it has a short waterpump with a two groove pulley, the crank pulley is a 3 groove, single groove ps and ac. I believe the timing cover to be correct with the tab at about1-2 o'clock. Everything I've read says the short waterpump is right, but I question the pulleys. Should I go back to the old balancer and use the pulleys that I know fit? Do I even have the right pulley arrangement?

[rustytruck50]

Does anyone have a picture of what the original crank & water pump pulleys look like for a '72 with ps & air?

[sick472]

I am sorry I can not help with all the bits, pieces and parts proper for the front of a 72, but just in case you may have overlooked it...You want the #1 cylinder to be TDC on the compression stroke not the exhaust stroke.

[rustytruck50]

I will definitely recheck myself on that....I've not had this much difficulty in a very long time! My parts guy at O'Reilly said that possibly the balancer was miss boxed or something like that....I did stop cranking down on the install tool once I felt resistance, so I don't think I pressed it on too far....it's a frustrating thing

[superhondaz50]

I went through this BS this week. Had to use a 1/8" spacer on the crank and water pump, left the alternator and AC alone, they line up good enough. I'll try to snap a pic tonight if I can get my belts on.

[rustytruck50]

The "enjoyable ship" has long since sailed on this project and that would really be helpful...thanks!

[Keystone_Hate]

The balancer needs to be torqued, 60 ft/lbs i think. Going until you feel resistance may not be enough to line things up. Also, since the first balancer wasn't right, the pulleys may have been cobbled together from something else to make them work. I would double check and make sure you have the correct pulleys.

[GASoline71]

Your alternator is located on the drivers side? And you have a short water pump?

I have a 1972 GMC C15 with a 350 and all the stock factory original brackets and pulleys. Still has the original balancer too. I'll take some pics when I get home from work tonight.

Gary

[rustytruck50]

Originally Posted by Keystone_Hate

The balancer needs to be torqued, 60 ft/lbs i think. Going until you feel resistance may not be enough to line things up. Also, since the first balancer wasn't right, the pulleys may have been cobbled together from something else to make them work. I would double check and make sure you have the correct pulleys.

I think that's the problem....I was trying to be careful... saw a pic on here that looked like my balancer & timing tab and my balancer is out about a 1/2 inch farther....also tried the center bolt and it doesn't catch any threads...

Gary, that would be extremely helpful....I do have my alternator on the drivers side with a short pump....haven't read anything lately on your GMC....how's it coming along?

[Keystone_Hate]

If the center bolt isn't catching any threads then you might still have the wrong balancer. Are you installing the woodruff key correctly?

[rustytruck50]

Well, I've had a couple of people tell me that the balancer will more than likely need to be cranked down a bit more....I didn't do anything to or move the woodruff key & it looked alright when the old balancer came off. Maybe I need to take it off and compare it to another of the same number?