[392cobra]

I'm trying to find out what the diameters are for stock pulleys for the water pump,crank and alternator.This is for a 351w,that is now a 418w.

Looking to figure out how much the factory overdrove the water pump and alternator.

While I had the 392w cooling was never a concern with the March performance pulleys.The Spal 16" fan and Griffin 2 row,1.25" tubes radiator did a fine job.
The radiator is rated for up to 600 hp.

I now have a 602 hp 418w and in slow traffic in 80's degree the water tempts go to 200 - 210*.
I have completely gone thru the cooling system and all is operating as they should.
I called Griffin and told the tech people the story. The first question they asked is "Are you running March pulleys ?".

They said that March performance pulleys were the #1 cause of low speed cooling problems when the radiator capacity is being pushed a little.

March perf. pulleys underdrive the pump 12 %.
I have ordered their Street Rod water pump pulley.It will overdrive the pump 5 % .

Any help with the diameters of stock pulleys would be appreciated.