[rknrl69]

this is driving me nuts. 1969 gto originall 400ci a/c convertible. Original block had small crack in cam journal. Installed 73 yc 455. added aluminium water pump. tried to installe pully's balancer pully to water pump is off 1/2 inch. car was produced 3rd week july 1969. the early 69's had the short water pump. what is the differance? help car show is 4 weeks 98% done.

[rknrl69]

this is driving me nuts. 1969 gto originall 400ci a/c convertible. Original block had small crack in cam journal. Installed 73 yc 455. added aluminium water pump. tried to installe pully's balancer pully to water pump is off 1/2 inch. car was produced 3rd week july 1969. the early 69's had the short water pump. what is the differance? help car show is 4 weeks 98% done.

[smoky]

Are you using ALL the pulleys from your 400,or the pulleys from the 455? I had that problem when i pulled my 400 and put a 455 in my 70 goat. All i had done was accidentally mix up the pulleys between the two motors,and they apparently had just a little bit of offset difference.Also is it a factory balancer or aftermarket?

[runningbwdog]

Hi,
The 70+ Pontiac engines used an 11 bolt water pump. The shaft is longer. You will have to find a water pump pulley for the longer shaft water pump. Did your 73 YC motor come with one? I put a 70 YH in my 68 GTO and had the same alignment problem till I put the right water pump pulley on it. As a side issue, are you going to use a flex fan or a clutch fan? The longer shaft will move the blades farther forward in the shroud. The flex fan makes a lot of noise when it is decellerating. You may want to consider using a clutch fan.
Hope this helps.
Mike

[rknrl69]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by runningbwdog:
Hi,
The 70+ Pontiac engines used an 11 bolt water pump. The shaft is longer. You will have to find a water pump pulley for the longer shaft water pump. Did your 73 YC motor come with one? I put a 70 YH in my 68 GTO and had the same alignment problem till I put the right water pump pulley on it. As a side issue, are you going to use a flex fan or a clutch fan? The longer shaft will move the blades farther forward in the shroud. The flex fan makes a lot of noise when it is decellerating. You may want to consider using a clutch fan.
Hope this helps.
Mike </div></BLOCKQUOTE>

[rknrl69]

THANKS YOU VERY MUCH. YES THEY ARE THE ORIGINAL 400 PULLY'S AND NEW GM BALANCER. NO THE 455 DID NOT HAVE ANY PULLY'S OR BALANCER WITH IT. ANY ONE HAVE A WATER PUMP PULLY FOR A 73 455.

[Shadowjack]

You have to keep the brackets and pulley sets together. You can't use a '73 pulley on a '69 bracket set. The bracket sets run '67-'70 and '71-'79.
There is a short '69 pump, which is about 4" long, and a standard '69-up pump which is about 4.5". They are all 11-bolt pumps. The factory usage of the short pump always causes discussion (maybe '69 Firebird only, but I'm not saying that), but they're not nearly as common as the longer one, being a one-year/one model application.
A '69-'70 pulley (those years only) for the long standard pump should not be too hard to scare up. There were several diameters and single and double grooves available.
Your pulley has a part number and a code stamped on it. It would be interesting to know that info for a 4" pump, if that's what you have. We can match the pulleys and pumps by the numbers in the parts book, but it's confusing to me as to which numbers are for the short pump.