Most, if not all A/C equipped Buick 455's came with a 7 blade 18" fan with a thermal fan clutch. I can't really see from your picture, but it looks like a flex fan possibly. This is an example of the fan clutch, https://www.rockauto.com/en/moreinfo.php?pk=815302&cc=1379763&jsn=420 The fans you can find, shop around. Thermal. The stock set up has 4 studs that screw into the water pump flange. The pulley slides over the studs, and the fan clutch slides over the studs and is secured with 4 nuts. The fan bolts to the clutch.
Looks like 4 or 5 blades. Looks like you have 71-72 Fan shroud which has a 22" opening. There are 20" GM clutch fans that will fit that shroud very nicely.
Appreciate that. My major concern is that the crank pulley and fan pulley do not line up. I do not know which is incorrect. Im assuming the water pump though needs changed?
Here is what my known items are. In the car: 1970 gs 455 motor Alternator is an ultima R111648A that is 78 amps Ps pump and pulley: unknown, cannot find a number or tag anywhere. Water pump- unknown. When wife is home with the car, i will check shaft. Extra parts the guy gave me: Ps pump - cardone 20-6800 Alternator- powermaster 17294 I'm mechanically able to change the parts. I just need to know what i need to get to make this work. Here is a picture from the bottom crank pulley looking up as well. So for the shaft, i take the bolts off the end of the fan, then measure the amount of shaft sticking out, correct?
Read through the links I posted for you. I believe they list part numbers which you will need to check. The 70 engine should have the short pump. I wouldn't be changing that, I'd just get the right pulleys. Somebody will have some for you. Figure out what you need first.
Maybe im dumb, but if we assume the pump has the short shaft, then you think i can change the pulley on the crank and be good?
My 70 has the short pump. My belts line up fine. I don't know which of your pulleys are wrong. It might be the fan pulley. The part numbers may be in a spot that requires you to remove the pulleys to see them.
Ah, so the fan may be the culprit. Possibly the pulley, clutch and fan replacement and i may be good? I can do that. I will see if i can get to the numbers on the fan pulley. Does that pulley just bolt on or is it pressed on?
Maybe a picture will help. I'm not sure where you have your belts. The P/S should be the inner most groove on the crank pulley. The A/C is the middle groove on the crank pulley. The fan, water pump, and alternator, are on the outermost groove of the crank pulley. The fan pulley has 2 grooves, the inner most for the A/C, the outer most, for the fan, water pump, and alternator. The fan pulley simply slides over the 4 studs that thread into the water pump flange, then the fan clutch slides over those same studs, then 4 nuts secure everything together.
Awesome, thanks. Now if i do not intend in the near future to put ac in, do i need an alternator with 2 pulleys? The powermaster 17294 says it fits a 1970 gs 455
The fan pulley DOES NOT press on. In your set up, there are likely 4 bolts that bolt the fan, pulley,and spacer directly to the water pump flange
No, the alternator single pulley is fine. You will need to use the grooves in both the crank pulley and fan pulley meant for the A/C.
Measure the opening of your fan shroud first. Should be about 22". If so, use the 19.5" 5 blade or 7 blade GM fan. I believe this fan should work. https://www.summitracing.com/parts/...MIr9_N_-iV6wIVCZSzCh20fwoKEAQYASABEgJ8uvD_BwE
I will check the opening then. If I go with this fan, that will work with the fan clutch you posted before? the Four Seasons 36956
Larry please correct me if I’m wrong, but in the picture it looks like the PS belt is routed over the fan pulley. I have mine routed & thought the PS belt just went around the crank & PS pulley. I have the 3 groove crank pulley though. Not sure what crank pulley the OP has. Kyle
A buddy came over last night and he said the same thing. I will be changing the around as larry has been awesome and patient with me. The last owner had the belts in the wrong grooves and you are correct, the ps belt needs to just go direct to the crank pulley.
Which since you have a single pulley would then move the ALT belt back a groove to help with alignment. That groove would be correct If you decide to go back to the double groove ALT pulley. Kyle
