Race crank pulley
 

Does anyone have any experience with these?
I was thinking about running this with a underdrive water pump pulley and keep the stock alt. pulley.

Any ideas?

eBay Motors: 83-93 Mustang 5.0 GT LX Cobra Race Crank Pulley Pulleys (item 8034725730 end time May-25-07 23:38:43 PDT)

Sorry.

I would only run that if it was an all out drag car. just my 0.02

What can it affect?

I ran one on my coupe years ago using an "OVERDRIVE alt pulley (really small alt pulley)" and when at idle you'd see the lights dim, many many times did I have to get a jump if I couldn't push start it and it killed my battery, so I got rid of it and went back to the underdrive crank pulley.

Yeah I was gonna keep my stock alt pulley but I don't think I follow you on whether or not to run a race crank pulley.

leave 3 inch pulleys for race cars, just run the underdrive

WHAT DOES IT AFFECT!!!!
Why is it JUST FOR RACE CARS? I'm trying to ask a FORD TECHNICAL question here!!!

it will not spin the water pump enough to cool the engine, and will not spin the alt enough to charge the battery

ie if it is half as small the other pulley's move half as fast.