Blower pulley

[JeffV8]

I'm running a 331 Chrysler hemi in my falcon. I have a 6-71 blower and 4 port Hilborn.  This will be a street driven car most of the time.  Question is what size pulleys to use?? Plus what pitch to use.

Thanks

[Paul New]

with the theme of your car I would run 1/2" pitch, maybe a 36 on top and a 32 on the bottom 11%UD or 35/32 8.6%UD

Not sure of your compression or fuel you would be running

[JeffV8]

I'm guessing around 8:1 for pistons and run on gas. I was thinking 1/2" pitch.

[digster]

 I'll bet you'll be fine with Paul's recipe. For a little more boost you might consider a MSD boost retarder. Mine allows me to run mid grade gas in my street rod.  An 8-71 at 1 to 1 on a 525 BBC.

[Paul New]

i think 6% under driven would be a good start

[JeffV8]

Thanks for the info 👍

[JeffV8]

Do all 671 snouts have 1 hole that is off set.  Do I have to elongate the hole on the pulley or just run 5 bolts.

[Paul New]

I believe Weiand is the only company that uses the offset hole use all 6-bolts just elongate the one hole

[JeffV8]

That figures. I get the oddball snout. Thanks Paul.