Large fan no shroud or small fan and shroud?

[diesel_lv]

My crank pulley diameter and water pump pulley diameter are the same. I've just ordered a Flowkooler pump. I'm wondering if I should try to locate a smaller diameter water pump pulley to overdrive it a little, to assist in cooling when at idle, which is where I'm having the issue. Both pulleys measure out at 6.75" as best as I can tell. Maybe the Flowkooler pump alone will do the job.

Yes, your WP should be overdriven. I use a flowkooler n my water pump is o/d. Again, in 125° mine works great. In 90°, I can barely get 196 at idle w 180 stat.

 

[Mark1972]

Apparently the undersized(overdrive)water pump pulleys were used on HP 383's and 440's. A local guy has two, and is holding one for me. So I'll be able to add the overdrive pulley and the Flowkooler pump when I'm home in a couple weeks. As always, thank you so much to everyone for all the guidance and advice. I'll post again when it's all done end of July.

 

[JG71B]

Apparently the undersized(overdrive)water pump pulleys were used on HP 383's and 440's. A local guy has two, and is holding one for me. So I'll be able to add the overdrive pulley and the Flowkooler pump when I'm home in a couple weeks. As always, thank you so much to everyone for all the guidance and advice. I'll post again when it's all done end of July.

I recently installed a smallblock WP pulley. Same depth smaller diameter. I can take pics if needed. Made a big difference. Also added the same Mancini shroud and Water Wetter. I dont go over 195 at all now in all conditions. Before I would overheat from sitting and or ildling after a while.