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Can I mix and match pulleys on my '86?



I have an unusual problem. The previous owner of my '86 put a smaller crank pulley and alternator pulley on the motor. I does not charge well at idle. Can I retain the smaller crank pulley and go to the smaller alternator pulley to speed it up? If I do this, the belt will be somewhat too long. Is there a formula I can use by measuring the larger hi-performance alternator pulley in comparison to the smaller stock pulley to determine new belt length? Are there many belt lengths to choose from at, say, Napa?

(I also have the stock crank pulley, but when I tried to install it, it hit the crossmember!!!)


the last three digits of the serp belt part number are the belt length as meaured at the ''working point'', technically refered to as ''pitch diameter''....so an xxxxx885 belt is a half inch longer than a xxxxx880 part number belt....most auto parts stores will be happy to let you buy a belt and return it unused within the same day to trade for a longer or shorter one IF YOU TELL THEM FIRST that you are trying to find the correct one (small price changes may apply due to length changes)....use the indicator on your belt tensioner to determine right belt.

in the length range possible for the vette, there are normally stocked belts at napa and most discount parts stores in half inch (and less) increments.


Okey dokey. That is good info that I did not know. Thank you very kindly.

Black Bart

The crank pulley is easy to change. Go to a salvage yard and get a pulley from a SBC and put it on. This will be as easy as changing the pulley on the alternator plus is will speed up your water pump and power steering.

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