Hi guys!

I swapped a Cummins 4BT into my '67 Dodge Town Wagon [that I've been driving since about '77!]. Engine was out of a Grumann/Chevy P-30 stepvan, so it had a GM alternator, that I upgraded to a 12SI. I want a Mopar alternator! Problems with dead batteries lately...

I happen to have 3 of the 70's vintage Chrysler 120 amp Police - Fire - Ambulance alternators. Problem is they're vee belt drive and the Cummins 4BT is 6 groove serpentine.

Anybody happen to know the shaft or pulley size for the Cummins 6BT alternators? Or have you ever seen the old style 120 amp alternator on a 6BT or with a 6 groove serpentine pulley? I'm hoping to do a pulley change and fab up a bracket and be making some major MOPAR amps!

Thanks!

 

both my 4bt's were 8 groove, 1 with v belt vacuum pump, the gm internally regulated alternators come with 150 amp upgrades, far superior with 40 amp idle output, if you want the serp pulley to Chrysler, find your local auto parts rebuild supplier, or look up a1-cardone, national rebuilder.

 

Thanks for the info, Sooty!

Actually I don't know on the 6 groove versus 8 groove on the pulley. I was thinking 8 groove then I saw on the 4BT Swaps forum several guys said 6 groove. It was really storming last night so I couldn't check it myself. I'll check it out today when I work on it.

That GM upgrade sounds good, I'll also check that.

I ran the Mopar 114A-120A Police - Fire - Ambulance alternators for years and had great performance out of them so I wanted to stick with a winner, at least for me. Just a pulley swap and some fabbing for a mounting bracket and I'd be in business.

Thanks again!