Need to adjust the boost on your Whipple equipped 99-04 Lightning or 02-03 Harley Davidson F150? Then look no further as Whipple manufactures these high quality pulleys in several different sizes, ranging from 2.50" all the way up to 4.25" in .250" (1/4") increments. A rule of thumb is that each 1/4" of pulley diameter is about 2 psi in boost change. The pulleys are machined from billet aluminum and then black anodized. No special tools required for installation as they are secured with the same 4 allen head bolts used to mount the original pulley.
