under drive pulleys?

[only 31s]

any one have used these? can you feel any additional power or just waste of money---stock 1990 350 w/headers engine ,suburban. thanks

 

[dyeager535]

Normally not a good idea for anything other than an application that turns so fast that the waterpump is overdriven and cavitates.

Slower rotation at idle is really not a good idea. Lower output from the alternator, and worse cooling.

Save your money for something that has real performance benefits.

 

[80' 427]

pretty much a waste of money.