72 GMC SBC pulley - The 1947 - Present Chevrolet & GMC Truck Message Board Network

camelot · 06-12-2003, 02:01 PM

OK, I am swapping parts from one engine to another and mixed up the pulleys that go on the front of the dampener.

I have 1 that is a double groove, one piece, kinda bell shaped pulley and another that is 2 pieces, both are fairly flat and they fit together to make the double groove for the 2 bets.

Which one is the right one???

My truck is a 1972 GMC K1500, 1/2 ton, 4x4, 350 engine.

TIA

**CPNE** · 06-12-2003, 02:17 PM

Are you running the stock accessory brackets for a 69-72? Also do you have PS? Neither one you describe sounds correct, though he first one sounds more like the fan pully rather than the balancer pulley. The stock setup balancer uses 3 grooves (a/c) or 2 grooves with a spacer (non a/c). The alternater runs off 1st groove (closest to engine), the PS off the outermost. A/c runs off the center. If I had to guess, the second set sounds more correct. Got pics or part #'s?

**Desert Rat** · 06-12-2003, 03:36 PM

double groove one piece if its stamped steel sounds like a later model long pump pulley.your correct pulley should be a flat 1 piece(or 2 if you have AC) and a 1 groove pulley thats dished that fits inside the the flat style pulley.

**CPNE** · 06-12-2003, 04:01 PM

What Micah said and I meant to say is that the 69-72 stock balancer pulleys are 2 pieces that when put together give you 2 or 3 grooves.

camelot · 06-12-2003, 05:59 PM

Ok, I'm going to go with the 2 piece (good thing too because I already cleaned and painted it).

I can always change it if it is wrong. I am not the original owner and the guy I got it from just kinda pieced it together. I'm playing the guessing game right now as to what should be there and what shouldn't be there.

Thanx for the help!!

06-12-2003, 02:01 PM	#1
camelot Registered User Join Date: Apr 2003 Location: Santa Clara, CA Posts: 39	72 GMC SBC pulley OK, I am swapping parts from one engine to another and mixed up the pulleys that go on the front of the dampener. I have 1 that is a double groove, one piece, kinda bell shaped pulley and another that is 2 pieces, both are fairly flat and they fit together to make the double groove for the 2 bets. Which one is the right one??? My truck is a 1972 GMC K1500, 1/2 ton, 4x4, 350 engine. TIA __________________ Camelot www.toyotagirl.com 1985 Chevy 4Runner 1972 GMC 4WD

06-12-2003, 02:17 PM	#2
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	Are you running the stock accessory brackets for a 69-72? Also do you have PS? Neither one you describe sounds correct, though he first one sounds more like the fan pully rather than the balancer pulley. The stock setup balancer uses 3 grooves (a/c) or 2 grooves with a spacer (non a/c). The alternater runs off 1st groove (closest to engine), the PS off the outermost. A/c runs off the center. If I had to guess, the second set sounds more correct. Got pics or part #'s? __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

06-12-2003, 04:01 PM	#4
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	What Micah said and I meant to say is that the 69-72 stock balancer pulleys are 2 pieces that when put together give you 2 or 3 grooves. __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

06-12-2003, 05:59 PM	#5
camelot Registered User Join Date: Apr 2003 Location: Santa Clara, CA Posts: 39	Ok, I'm going to go with the 2 piece (good thing too because I already cleaned and painted it). I can always change it if it is wrong. I am not the original owner and the guy I got it from just kinda pieced it together. I'm playing the guessing game right now as to what should be there and what shouldn't be there. Thanx for the help!! __________________ Camelot www.toyotagirl.com 1985 Chevy 4Runner 1972 GMC 4WD

06-12-2003, 03:36 PM	#3
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	double groove one piece if its stamped steel sounds like a later model long pump pulley.your correct pulley should be a flat 1 piece(or 2 if you have AC) and a 1 groove pulley thats dished that fits inside the the flat style pulley.



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