Topic: 1968 390/428 Alternator

[sah62]

I'm trying to determine which alternator was originally used on 1968 Mustangs equipped with a 428 CJ engine.  During the course of my research I've found build sheets marked with both "38" and "55", which would seem to indicate 38 and 55 amp alternators.  All of the 428 CJ build sheets are marked "38".  The "55" appears on a build sheet for a car with a 390 and air conditioning.

My April 1970 MPC identifies the 38A service alternator for all 1968 6 and 8 cylinder Mustangs as C6DF-A or -B.

An April 1968 printing of the AMA passenger car specifications document identifies the 38A alternator used for 390 and 428 Mustangs as C6TF-A, an alternator equipped with a single-sheave pulley.  The MPC also lists a C6TF-B listed with a double-sheave pulley, but it doesn't list the -B alternator as a service part for 1968 Mustangs.

So, what's the concours-correct view?  38A alternator for a 1968 Mustang equipped with a 428 CJ and no a/c?  If so, which one?

[CharlesTurner]

I have an original from a '68 CJ engine and no A/C.  Doesn't the thickness of the stator bands determine the amperage?  I could get it out and snap some pics if it would help.  Pete Morgan has my copy of the '68 single year MPC, he can look it up when he gets back home later this week.

[sah62]

Thanks, Charles, I'd appreciate any pictures and MPC info you can find.

[T Lea]

Regarding the pulleys, since all 428s were thermactor equipped it is simply no AC=double pulley. AC=single pulley. The 68 mpc isn't much help as it lists all those alternators as 38a and for a Mustang chassis. Some believe all CJs used 55 amp regardless of what the build sheet listed. Just to add to the confusion, non ac/CJ 428s (GT 500) used 42 a alternators

[sah62]

Some believe all CJs used 55 amp regardless of what the build sheet listed. Just to add to the confusion, non ac/CJ 428s (GT 500) used 42 a alternators

All of the non a/c Shelby GT500 build sheets I've seen say "38", too.

[CharlesTurner]

Here's some pics of the original alternator I have.  It came off a CJ without A/C, but I couldn't tell you for sure what kind of car it was in.

http://www.early-mustang.com/charles/11_10/alt/

[sah62]

Hmm, orange marking - 42A.  Can you make out the engineering number, Charles?  I see what looks like a C6, but that's about it.

[CharlesTurner]

All that is readable is 'C6', sorry 

[sah62]

When I blow up the picture a bit I think I can see an "A" after the "6", and maybe a "C" under the second AUTOLITE "T", which would be consistent with a 42A C6AF-C alternator.