340 Water pump and alternator belt size

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Tanman74

Tanman74

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I've been building a 72 340 and I'm about to put it on a run stand but I need to get belts for the alternator and waterpump pulley(I'm not running AC or ps until I get it into the car), I've played with some belt sizes but so far I haven't found the correct size. I just got back from napa with 7430 and a 7425 for the alternator and 7350 and a 7345 for the water pump, I buy one of the next size down to save trips. Just running the waterpump pulley to the crank and alternator to the crank, the engine originally had ac and I have the pump still along with a two groove alternator although I'm unsure how long I'll keep the alternator since the none of the bolts I have fit in the front cover for the adjustment.
 
For mine the waterpump uses the first pulley on the crank and the alternator uses the second and third. From what I've seen and guesstimated the alternator goes to the AC around to the crankshaft with two belts and the waterpump and ps use the same belt.
 
You would know better than me. My 340 going into 68 Barracuda is a non PS and non AC car. Very simple but fought the pully problem with slow and expensive success. Single pully alternator and water pump. Does your alternator and water pump grooves line up? I'm assuming not. You may be required to change water pump pully to mate with alternator.
 
I see in your post they use different grooves on crank so they do not line up. Consider different water pump pully.
 
Save yourself some aggravation and get the correct non-AC pulleys


Alan
 
Just get a bit of rope and wrap it around your pullies and mark where they join
then cut at that mark then take it to the spare parts store and they should be able
to measure he rope and give you the right length for your belt.
This is what I have done with my engine!
 
How do you plan on getting the water pump belt on without some sort of idler or adjustable third point like the alternator?


Alan
 
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