I spoke to a tech at Powermaster about 9 months ago.  Their website is http://www.powermastermotorsports.com/alternators.html.   They said that they could make the 2 wire 6 volt positive ground unit for the Thunderbird and it would be no problem.  They do not have them available right now.  The only thing I didn't like about the Powermaster PowerGen generator is that they do not use a keyed shaft for the front pulley/fan.  I had to replace this on my 12 volt 57 Ford because I have factory air and I didn't get it on tight enough and it slipped.  It would not have been a problem with a keyed shaft.  Other than that, I am sold on their products.  Dan

tater sal;  I have a good 55 generator from my 55 T-bird , I changed over to an alt 12 V.

My e-mail is fairlanebob@charter.net

Phone  530-526-3413  cell

Bob  Harvey

I am sorry, I was misinformed.  I did speak to them several months ago and was told that the 2 wire system could be made.  I contacted them again, since I am almost ready to replace my alternator and I was told they could not do the 2 wire on the 6 volt positive ground.  I think they are concerned that the demand would be too low, as I do not see why they can't make the 6 volt unit the same as the 12 volt model.  I apologize..  Too bad, because I like their 12 volt units.