I am building a Whipplecharged 502 EFI and the engine coupler I have has worn splines. It was off a Magnum engine and has an aluminum hub, as does the replacement part number. The 500 EFI shows that it uses either aluminum hub PN 861523A9 or a steel hub PN 861523A19. Why are both offered and is there a fit difference or a disadvantage to the steel one? Seems like it would wear better but maybe wears the drive spines? Any comments are welcome.

I ran a 575 steel hub coupler behind 900 +hp in my Baja for over 400 hours, i didnt see any spline wear fwiw, smitty

I believe the aluminum ones were used up to 400hp and the steel ones over 400hp

Any advantage/disadvantage to using one with the long hub versus the short hub?

The long hub is by far the best as you have to have close to perfect alignment to get input shaft in plus it supports shaft, i had same ujoints for over 400 hours behind various blower motors and they are still like new today. Disadvantage is its difficult to get motor in with longer snout unless you have extra room.

How often do you guys lubricate the coupler? I had a horror story - last year- which is posted someplace in the bowels of OSO trying to lubricate it -- with a Harbor Freight grease gun --- URGH-- NEVER AGAIN. I do ours once year with the special grease/elixir.

thanks

3pointstar

Every 25 or 30 hours, i know guys who do it once a season

FWIW I have about 10 of the short aluminum versions as the HP 525 and the 600 Sci used these as well.

All brand new shipped to your for $ 475 bucks if anyone is interested