[new indian]

I have a 77 400 with power steering. My question is which of the 2 pulleys I have to use. 1 is from the 77 motor the other is from a 71 350 which is smaller. the 77 is about 8.25" diameter and the 71 is about 6.5" dia.
what are the pros and cons of each?
Thanks

[lastchancegoat]

Just went through the pulley nightmare. My engine is a collection of parts (68 core) plus a lot of new aftermarket stuff. Had only the crank pulley to start with. It boiled down to which pulleys line up. Still needed a spacer made by ace machinist Jeff and this was after he came over with a large box of Pontiac pulleys - each a different diameter and offset. Big pulley v. small pulley really has to do with the speed at which the pumps spin. In the end I don't think this is as important as getting correct lineup. If it a true restoration (mine is a street beast) it would matter. One could argue pump speed all day but in the end, stuff gets pumped. Go for proper belt line up - just my $.02.

[Formulabruce]

71 is iron 3 spoke, later is stamped steel. I think youll find more (pulleys around) to align with the 350 pulley

[new indian]

I've worked the alignment out to where I can use either one. I guess the question is water pump speed? Like lastchancegoat said the question could be argued all day. But, I'm interested in any theory anyone has!
Thanks

[Geoff]

Check out

www.stewartcomponents.com for pump speed.

Under Tech Tips.

[PLAY400]

Do a search on pulley sizes. There was a recent post and I believe it stated that the larger pulley was used on AC cars. This seems to match what I have at home. The pulleys off my 72 Granville 455 e/w AC have a large bottom pulley and a 6 1/2" waterpump pulley. My non AC 400 has a 6 1/2" crank and water pump pulley. Temperature in the 400 creeps up on highway??