Chevy 250 Straight Six AC & PS Help Needed!!

[jagvic]

Hey Guys,

I'm trying to install AC on a 75 Chevy 250. The car originally started off with PS, so there were 2 groove pullies on the balancer and water pump which drove the alternator (groove closest to block) and PS (second groove away from block). I purchased some AC brackets and pullies and installed them with a compressor. The pullies were add ons for both the crank and water pump so that now each has3 grooves. I was told that in the original installation when you had AC that it was driven by the second goove away from the block, and that the PS belt is moved out to the third groove away from the block. Upong installing the AC I see that yes it aligns perfectly with the second groove. Then again, so does my PS pump pulley! So I need to somehow move the PS pulley further forward (away from the pump) and I already have a single groove, flat pulley. Do they make ps pumps with longer shafts, or was there a pulley that was an INVERTED bell (ie the groove is completely forward of the end of the pump shaft OR did they have different brackets to mount the pump in AC cars??? I am at a real loss what to do! Thanks for all the sage advice I know I'm gonna get from you guys!

[andyh1956]

man i went through that stuff with a 250 i put into a m715. i needed p/s- found it on bout same model truck you have. had to go back & get water pump also! i think you just need to get another p/s pully w/ two groves in it. it was common to see two grove pullys on pumps w/ only one grove used. good luck!
andy

[jagvic]

Well i have seen the 2 groove pullies but they always seem to have the second groove closer to the pump - has anyone ever seen a 2 groove pulley where the second, added on pulley was in FRONT of the first?? Or does anyone know of a single groove press-on PS pulley that stuck out fursther than the flat kind that came on just about everything? I'm really at a loss here and appreciate any help - thanks!!!

[andyh1956]

ok- your alt should be on lower left side of engine next to steering gear? and p/s pump on top of that? kinda bolts to water pump & ex maniflold? and freon comp will mount on right side of engine? and does p/s pump have only one groove now? it was common for the short water pump small blocks [283 & 327] engines to stack pulleys so that part is probably ok. still sounds like you need a pump pulley that will reach the front groove. i'm a long way from a six cyl expert but could you space pump/bracket assy forward? i would check over at the inliners forums- find more experts maybee. also go dig through the old parts books- not computer- at local chevy dealer. keep us posted!
andy

[andyh1956]

new idea- maybee install 2 groove pulley backwards- it might reach others but without flange you may never get it back off!
andy