I have a 67 with a fresh 396 SWP with billet pulleys, I've heard of the string trick to measure for the belts but where do you wrap the string around , the outside of the pulleys or the bottom of the groove to get the length you need ?

Also , I have noticed when I rev the engine up some the alt. belt will squeel , the belt seems to be tight enough , any thoughts ?


Thanks , Rick

I have always used the bottom of the groove. It always gets you close. I have had to make adjustments in the past.

I use the bottom the groove as well. I measure with the adjustment at both extremes to get a range of what will work.

I have noticed when I rev the engine up some the alt. belt will squeel , the belt seems to be tight enough , any thoughts ?
Paint or clearcoat on the pulley groove? No traction between belt and pulley?

Remove the paint, and either replace the belt or deglaze the working surface of the belt.

I like the Gates Kricket for belt tension testing.