im a little late to this thread, but as mentioned if original isnt a concern i use & like the PRW aluminum pump. it has a cast impeller but the vanes have been machined to a cleaner shape, not sure what the benefit of that is but they felt it was worth it to do as opposed to just leaving them rough cast. it also was very close to the divider plate & only required minimal effort to get a tighter clearance. i run a 467 E-head stroker with only a budget 3 row alum radiator & the car runs at 180-190 in all situations from hot summer street driving to drag racing.
anyone have opinions on the machined vanes?
https://butlerperformance.com/i-3164...w-1445500.html