I just want to double-check that I have the stock crank pulley on my 2000 Silvy with a 5.3. I am also about to install a smaller pulley on my Whipple and want to calculate how close (or far) I am from the max rpms for the Whipple. Yea, I could just crawl underneath and measure it the crank pulley, and I will, just not tonight . I just want to compare my measurement to what someone confirms to be the stock diameter. Does anyone know the diameter of the stock crank pulley?

Scott

 

It is about 7 1/2 inches give or take a little.

 

I'm thinking 7.4" I'll measure the one I have laying around and post the correct size tomorrow.

 

It measures 7.56"

 

L-Eater and Whitt,

Thanks for the confirmation. Doing some quick math, that means with a 3.5" pulley at 5500 rpm the Whipple is turning at 11,785 rpm, which is below the 14,000 max rating (if I have been informed correctly). Just got the pulley this morning...I want to leave work just to see the effect

Scott

 

That sounds about right. The way I knew it was close to 7.5 is I have the 2 belt system and recently had a custom 7.5" lower blower pulley made and it is pretty much the exact same size as the factory balancer. I am running a 3 3/8 upper and it is around 8 psi.