8mm pullies

[hotrod316]

looking for some 8 mm pullies  42 and a 60 something close to  25% under drive thanks

[Paul New]

I do not have any for sale but a 42 top and a 60 bottom is 42% OD I may misunderstand your question though

[hotrod316]

UNDERDRIVE  -25%  BIG ONE ON TOP,  LITTLE ONE ON THE BOTTON I THINK
ONLY WANT 2 MORE  LBS   

[Paul New]

Ok 55 on top and a 44 on bottom gives you 25%UD or tons of other ways to get there. But I know most of the manufactured belt guards won’t fit a 60 tooth pulley on the top

[gregm784]

... But I know most of the manufactured belt guards won’t fit a 60 tooth pulley on the top

I can get a 58 on top, but unless the belt is SUPER tight, it'll candy stripe the back of it.

On a SBC with a RCD crank support, you can run down to a 53, but you have to relieve the I.D. of the lower pulley a tad bit. 

[dreracecar]

OD% (or Under) only equates to how soon the blower reaches full boost before it starts to cavitate.   5 over made the same boost as did the 18 over, but was a rocketship at the hit with the 18%