If I remember correctly there is a good article on alternator upgrading at turbobricks.com ( http://www.turbobricks.org/mods.php?content=gm_alt )I am going to be changing to an internal regulated 100amp gm alternator myself.
Best of luck
Ray
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keep the R's up!

I put a 70A into my son's 81, replacing a 55A. The 55 was a reman unit with internal reg. so it was an easy swap. The B+ terminal on the 70 was in a slightly different position - I had to pull all the slack out of the large red charging wire from the starter solenoid to reach the B+, and it's still pulled a little tight for my liking.

Main benefit of the bigger units is more amps at low revs.
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Bob (son's 81-244GL B21F, dtr's 83-244DL B23F, 'my' 94-944 B230FD; plus grocery-getter Dodge minivan, hobbycar MGB, and numerous old motorcycles)

I have recently replaced the '81 turbo's 55 amp alternator with external regulator to a 70 amp with internal regulator. It was a plug and play swap. The 70 amp alternator is physically larger and some have found it necessary to use slightly longer belts to clear the oil pressure sender, especially on the turbo models. The stock belt is 10mm by 925mm, the 10mm by 955mm makes installation a bit easier. The swap cured a lot of the electrical problems that I was having, especially eliminating the headlight flicker I was experiencing.


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don hodgdon '89 744ti, '81 242t, '71 D-35

Any of the later alternators will bolt on and fit well, 70,80 or 100. I haven't done a conversion from external to internal regulator so I'm not up on what may have to be done there.
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Dave Shannon
Spring Valley, California
'84-245T 190K+
'88-240 190K+
'65 1800S ????K
'73 1800ES 117K
'92 745Ti 150K
Jeep Wrangler Sahara 10K
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