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Discussion Starter #1
Hi

Can anyone advise a long water pump pulley for my 347? I have a cast iron long water pump on my 1986 302 block which is 5.4 inches front to back. I have a March pulley (MCH-2004) on it which is too short by about 1 1/4". I have tried spacers on the crank and alternator pulley's but would prefer to find a longer water pump pulley. Anyone got any idea's? I have spoken to March but didn't get the answer I needed.
I was thinking maybe a Chevy one may fit if I could find one with the same bolt pattern.

Any help appreciated as always

Martin
 

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I'm not sure what balancer you are running but the 5.0 style balancer sticks out further than the older style balancers did..If you have an early style pump it won't match up with the 5.0 balancer or vice versa.
 

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Discussion Starter #3
I'm not sure what balancer you are running but the 5.0 style balancer sticks out further than the older style balancers did..If you have an early style pump it won't match up with the 5.0 balancer or vice versa.
Hi
I'm using a new "professional products" balancer. I just really need a pully where the belt part (serpentine) sits further back to line up with the other two. I thought there would be millions of options out there!!!

Thanks

Martin
 

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Hi

Can anyone advise a long water pump pulley for my 347? I have a cast iron long water pump on my 1986 302 block which is 5.4 inches front to back. I have a March pulley (MCH-2004) on it which is too short by about 1 1/4". I have tried spacers on the crank and alternator pulley's but would prefer to find a longer water pump pulley. Anyone got any idea's? I have spoken to March but didn't get the answer I needed.
I was thinking maybe a Chevy one may fit if I could find one with the same bolt pattern.

Any help appreciated as always

Martin
How your saying whats needed doesnt make sense.

pulley bolt pattern really isnt an issue , can be redrilled
 

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Or like this guy on TFFN,

I've been slowly making progress this week. I think I will be able to finish assembly on my motor tomorrow. I still need to trick my carb and modify and restore the air cleaner, but the front dress is now looking dialed. I built a custom water pump pulley from the stock 5.0 reverse rotation and the '79 crownvic standard rotation pulley to get the correct offset. I turned both pulleys down, and added a shoulder with a .002-.003" press fit, tapped them together and then had to pay $25 to get them TIG welded together (I don't have access to a TIG, and the my MIG is just not the right tool for the job). I used Bogue's Welding in Hayward CA, they had a bunch of hotrod in there shop, so it looked like a good place, nice work and it was ready the same day. After welding there was only about .003" runout which was as good as the factory. The only snag I ran into was the bolt pattern. I used the hub from the reverse rotation pump, and the holes didn't line up! I didn't notice the problem until after I was done machining, so I did what any self-respecting hot rodder would do, re-drill the hub and weld up the offending holes. Now I just need to wait for the paint to dry.

-Craig

http://www.tffn.net/phpBB3/viewtopic.php?f=59&t=21378&start=30
 

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Discussion Starter #8
OK, I have got a pulley which gives me the perfect alignment with a tiny bit of shimming. the original pulley was 5.5 inches diameter. The replacement is 6 inches diameter, will that make any difference and can someone explain to me about water pump pulley diameter please? I am reading about "underdrive" pulley's which I don't understand.

Thanks

Martin
 

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The bigger pulley on the water pump will slow it down some...This will take a little less hp to drive but it "may" affect your cooling as it will slow down the water flow a bit...Going with a smaller crank pulley or a larger water pump pulley slows down the water pump rpms...Underdrive kits often include both as there is usually very little clearance between the two pulleys..Sometimes there just isn't room to run just a bigger water pump pulley.
 
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