Pulley Size?

[vdubfund]

I must apologize

It has been a long time since my last confession.Ha!

What size pulley is best for my P fan??( original Porsche 11blade)I have been thinking either CSP (140mm??) or BAS has two. Race and regular.
The reason is, I was thinking I could get the same year 911 pulley as my fan,have it machined the for the crank hub and they should be great together!...... about 116mm .....at first i was thinking that was small, but if thats the size porsche made them .
Would overcooling by my issue??? The summers are hot and humid here in Japan. Very little expressway driving(there aren`t any FREEways here!) Lts of stop and go traffic

Cheers to all