350 crankshaft pulley

[jktacke84]

This is my first post on so bear with me. 1985 Chevy Silverado K10, Goodwrench 350, 700 r4 tranny, NP208 transfer case.
I have a slight wobble in my crankshaft pulley and want to change it out but I'm having issues finding a similar pulley. The belt drive was pulled off the previous motor in the truck which was a small block 400. The pulley is 3 groove with the outside groove is a little under 8" and the other 2 grooves are smaller in diameter. All the other pulleys I'm finding that are plain steel non performance have 3 grooves that are all the same diameter. Is there a significance in this or will I have any issues with a pulley that has 3 grooves that are the same diameter? I'm aware that I may need a longer belt on that outside groove if a change it. Any other issues that may come up? Any other problem with using 6 3/4" pulley if it is easier to find?

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[gunrac]

A quick google flipped this out. You need to know the length of your water pump.

http://www.speedwaymotors.com/Shop/Accessory-Drive-and-Pulleys-Engine-Crankshaft-Pulleys/12.html

[mattcureton]

I had the same problem. I bought a new Summit Pro Street balancer, and 8" steel pully from them.  It is flawless now.  You dont need performance pullys.  6 3/4" pully will underdrive your accessories a little