sendo Posted January 20, 2020 Share Posted January 20, 2020 changing pulleys to add a/c to my car and ran into a problem with the new crankshaft pulley hitting the fan pulley. cant find a 3 groove pulley that is the same size as the original 2 groove. is there one or is there a different size fan pulley? Quote Link to comment Share on other sites More sharing options...
Rob Peters Posted January 20, 2020 Share Posted January 20, 2020 That's a pretty big difference. Good luck in your search. Maybe some one in the club can help you out rob Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted January 20, 2020 Share Posted January 20, 2020 Summit has some listed but mostly aluminum. Quote Link to comment Share on other sites More sharing options...
jft69z Posted January 20, 2020 Share Posted January 20, 2020 I checked my stock lower pulleys from the 72 402. I have 2 of them kicking around here, (one I got from a dealer when I built an older Monte, different part numbers, but same pulley dimensions). Both are the same 7 11/16" as you have. The water pump pulley that was on the car originally is 6 3/16" diameter and has a GM part # 3995631AO. At least on my car, those are the stock pulleys used on a BB A/C engine. What diameter is your WP pulley? The WP pulley listed above seems to fit both small & big blocks. 1 Quote Link to comment Share on other sites More sharing options...
1970mcss Posted January 20, 2020 Share Posted January 20, 2020 What size engine are you working on?? 1 Quote Link to comment Share on other sites More sharing options...
sendo Posted January 20, 2020 Author Share Posted January 20, 2020 will have to take it off and measure it Quote Link to comment Share on other sites More sharing options...
sendo Posted January 20, 2020 Author Share Posted January 20, 2020 454 Quote Link to comment Share on other sites More sharing options...
1970mcss Posted January 20, 2020 Share Posted January 20, 2020 Parts book doesn't show size but it looks like it fits all the way up to 1975 70 Chevelle w /A ir Cond. (454), 70 Pass. w/C.A.C., A.T. (454), 70 Pass. w/Acc. Air Cond. (454), 71-72 All w /A ir Cond. (454), 73-75 All (454) ............................................. 3 9 3 7 7 8 7 1 12.90 PULLEY (3 groove) (Note 1) NO TE 1 N o t u s e d o n m o d e ls h a v in g A c c . A i r Cond. a n d 2 .5 6 o r 2 .7 3 a x le ra tio . Quote Link to comment Share on other sites More sharing options...
sendo Posted January 20, 2020 Author Share Posted January 20, 2020 2 hours ago, jft69z said: I checked my stock lower pulleys from the 72 402. I have 2 of them kicking around here, (one I got from a dealer when I built an older Monte, different part numbers, but same pulley dimensions). Both are the same 7 11/16" as you have. The water pump pulley that was on the car originally is 6 3/16" diameter and has a GM part # 3995631AO. At least on my car, those are the stock pulleys used on a BB A/C engine. What diameter is your WP pulley? The WP pulley listed above seems to fit both small & big blocks. don't have time to take it off till next week, but just measuring from the top of the wp shaft its bigger then 6 3/16. so that may be the problem Quote Link to comment Share on other sites More sharing options...
jft69z Posted January 20, 2020 Share Posted January 20, 2020 2 hours ago, 1970mcss said: Parts book doesn't show size but it looks like it fits all the way up to 1975 3 9 3 7 7 8 7 1 12.90 PULLEY (3 groove) (Note 1) That's the part number I have for the original lower 3 groove on my '72, except with an "AC" suffix. The superseded part number for the same sized 3 groove lower that I also have is 14025185BN Can you make out a part number on that pulley Rosendo? Quote Link to comment Share on other sites More sharing options...
DragCat Posted January 21, 2020 Share Posted January 21, 2020 Just throwing this out there, got this info from the parts place website. Crank 3937787 approx 7 5/8 and wp 3995631 approx 6 1/4. Those are listed for a 1970 BB 1 Quote Link to comment Share on other sites More sharing options...
sendo Posted January 21, 2020 Author Share Posted January 21, 2020 this is what I have, guess there is a difference with having a/c https://www.ebay.com/i/254181594636?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=254181594636&targetid=858513787104&device=c&mktype=pla&googleloc=9032210&poi=&campaignid=6470636538&mkgroupid=81597521470&rlsatarget=aud-622524041038:pla-858513787104&abcId=1140476&merchantid=7978624&gclid=Cj0KCQiAvJXxBRCeARIsAMSkApoWBY9JJGIc36j_GtE_Ai8SWMxlDnIGOMsQKrlGKbTBkhg2wFOeTQ4aAiM2EALw_wcB https://www.heartbeatcitycamaro.com/store/product/20884/1969-Camaro-Chevelle-Nova-SB-%26-BB-Water-Pump-Pulley-GM%23-3932402/ Quote Link to comment Share on other sites More sharing options...
jft69z Posted January 21, 2020 Share Posted January 21, 2020 Well that's good, mystery solved. Now maybe get one of those 3995631AO pulleys listed for an A/C car from ebay & you're good to go. There's at least a dozen to choose from, all in the same general price range. Quote Link to comment Share on other sites More sharing options...
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