[Healeys] Alternator conversion

[pvoris at q.com]

I'm sure this is a subject covered myriad times on the list, but I've missed it. I'm contemplating converting from the stock positive earth generator on my '56 BN2 to a negative earth alternator. Any suggestions as to which alternator will serve me best? What pitfalls should I watch out for in the conversion? Many thanks in advance to all of you who have been down this road before me! 

Peter Voris 
Las Cruces, NM 
'56 BN2 
'51 Riley RMB