I ntoiced for the 4000 series you need a smaller blet (as per the instructions) but for the 4010 (3 peice aluminum for 88-92 serp) coems with water pump, crank and alternator, it doesnt list a belt....does this mean i run my stock belt?

 

i think if you ran a search you'd decide not to use the alternator pulley

as to the length, you could always use the crude but effective string and ruler method

 

Thats only true if the alt pulley is larger then stock. If the set comes with a smaller then stock alt pulley, def use it to help speed the alt RPMs back up.

 

true, but i wasnt aware that march made "performance" pulleys designed to slow down accessories by being smaller and speeding them up