71 Altenator codes

[Carl Granquist]

I have a '71 coupe and I believe its "birthmonth" is April. I just checked the alternator housing after reading this and found these numbers - 1100950 42A 1C31 12VNEG. I don't have air conditioning and it's a 350CID/270HP 4SP. My question is this: if 42A stands for amps, then why is mine less than "gg82's" output of 61 amps? Is A/C the difference?

[Mike Ward]

Yes, it's as simple as that!

BTW, you can determine the birthdate of your car by using the date in the upper right hand corner of the trim tag.

[LemansBlue68]

Originally Posted by gq82

Thanks Chuck, just got an answer from Patrick on the NCRS board....looks like I have a correct alt with an incorrect date 4A7 = Jan 7, 1974....and from what he's telling me it's mission impossible finding an early 71 date....add it to my list.

Keep the faith! If you keep looking, you'll find one. You might try Goat Hill Classics in Long Beach, CA.

I looked high and low for the correct Q-jet (7028209-'68 427, std shift, Corvette only) for my '68. A lot of carb vendors would look up the number, laugh, and wish me luck. That's not very reassuring. I did eventually find a rebuildable core at a reasonable price with the correct numbers after a 2+ year treasure hunt. Many vendors who had one wanted $500 just for a core.

[Carl Granquist]

[quote=BTW, you can determine the birthdate of your car by using the date in the upper right hand corner of the trim tag.[/QUOTE]
Okay. I'm looking and I see either an "I" or an "l" and then "13" and I'm curious how this converts to a date?

[Mike Ward]

Originally Posted by Carl Granquist

Okay. I'm looking and I see either an "I" or an "l" and then "13" and I'm curious how this converts to a date?

It's the letter 'I'', which for the 1971 model year meant April '72. Letter 'A' was the start of production in August 1970. '13' is the 13th day of the month so I13 would be April 13th. This the day the trim tag was attached to the car. The car was finished that same day or up to 1-2 days later.