How do I tell what size pulley this is? I got a couple of extras when I bought the kit. Seller said one was a 2.75 and the other was a 3.25. I have the 3.4 on the Radix now. How do I measure the pulley to see which one I have because the other is missing in my garage, fat chance of finding it. Check out my pics and take your best guess. Measures from outside to outside on center at 3 1/8 inch. Thanks, Chris

 

looks like 3.25

 

What would be the inside measurements of a 3.2" pulley? If I wrap a piece of paper around the inside of the pulley (as if it were the belt) to wrap all the way around is exactly 9 1/4". I found the other pulley, its wrap around measures 8 3/4" so I just want to make sure they are 3.2 and 2.75. I also have a 3.7 that is marked. What uses that one, the 4.8L?

 

The 3.7 is what you swap to when you valet park or give the keys to a relative

 

LMAO...Or when you take it to the tranny shop for warranty work.

 

diameter x pi (3.14) = circumfrance
aproximate
3.7 = 11.6
3.2 = 10
3.0 = 9.4
2.75 = 8.6

 

 

There’s a reason I’m one class short of my Bachelors degree. It’s called Pre-Calculus Algebra, and I don’t do it. You’ll have to explain further ‘cause my measurements don’t equal your pi equation.

 

3.7" pulley measures in at 11 3/4" so...11.75 / 3.14 =3.7420382......
so my 8.75 pulley should be a 2.78 and my 9.25 pulley should be a 2.94 which would be rounded to be a 3.0? Hell I give up?