Uderdrive pulley

[juggernaut]

I'm currently rebuilding my engine and the underdrive pulley was cracked. I've seen various light weight pulley sale on eBay. My question is would i gain or lose anything by going with a aftermarket underdrive(crank) pulley which is lighter?

 

[te72]

ATI or stock, simple as that. Otherwise you're opening a can of worms that you probably don't want to deal with...