1970 LT-1 Alternator Pulley

[Joe L.]

Re: 1970 LT-1 Alternator Pulley

Here is the original on my LT1.
[ATTACH=CONFIG]119462[/ATTACH][ATTACH=CONFIG]119463[/ATTACH]

James------


Would you please measure and post the exact OD of this pulley?

[Gary B.]

Re: 1970 LT-1 Alternator Pulley

Here is the pulley on my 70, July 7th build. It measures 3.202" diameter and approximately 0.838" thick.
Gary Bosselman

2023-11-19 13.44.15.jpg

[Joe L.]

Re: 1970 LT-1 Alternator Pulley

Here is the pulley on my 70, July 7th build. It measures 3.202" diameter and approximately 0.838" thick.
Gary Bosselman

[ATTACH=CONFIG]119586[/ATTACH]

Gary------


The OD and thickness are about right. However, the aspect that seems unusual to me is the fact that the wider belt guide appears to be on the outer side and the thinner belt guide appears on the inner side. I have not noted that before, including the previously posted photos in this thread.

[Gary B.]

Re: 1970 LT-1 Alternator Pulley

Another picture... The front (closest to the radiator measure .120, the rear (closest to alternator housing) measures about .180"
I've owned the ole car since 1979. I know the alternator's been off when I rebuilt the water pump, but it's never been apart. I'll get a picture of Terry's tomorrow and post it. His is a Jan. 29th car.
Gary B

2023-11-19 16.58.47.jpg

[Joe L.]

Re: 1970 LT-1 Alternator Pulley

Another picture... The front (closest to the radiator measure .120, the rear (closest to alternator housing) measures about .180"
I've owned the ole car since 1979. I know the alternator's been off when I rebuilt the water pump, but it's never been apart. I'll get a picture of Terry's tomorrow and post it. His is a Jan. 29th car.
Gary B

[ATTACH=CONFIG]119592[/ATTACH]

Gary------

Yes, in this better photo it appears as I would expect.

[Gary B.]

Re: 1970 LT-1 Alternator Pulley

Terry's January 29th, 70 LT-1 is like my July 7, 1970 car. Not significantly different.
Measures about 3.2" in diameter. About 0.190 on the rear and 0.130 on the front.
Just a FWIW....
Gary B

2023-11-20 11.09.09.jpg

[Bob H.]

Re: 1970 LT-1 Alternator Pulley

i The first photos look like the adjust bracket is on the wrong side of the alternator and the alternator looks good. The restored car alternator looks great but I got dinged for it being painted and not "natural" like your first car So, I undid my pretty work! BTW, I now have the correct pulley!

[Leonard M.]

Re: 1970 LT-1 Alternator Pulley

"That alternator had the look of being untouched until I put my hands on it, to clean it, as seen by the adjuster bracket."
Yes, you are correct. That alternator had no evidence of ever being removed when I bought the car, but I removed it to clean and re-installed it with the adjuster bracket on the wrong side. Before realizing my mistake, the belt alignment didn't stand out as being off and the belt didn't squeel.

[Bob H.]

Re: 1970 LT-1 Alternator Pulley

Purchased 831 repro from Heartbeat and it would not slip on the shaft. I got one through Jegs but made by OER. Looks good and fit perfectly

[Joe L.]

Re: 1970 LT-1 Alternator Pulley

Purchased 831 repro from Heartbeat and it would not slip on the shaft. I got one through Jegs but made by OER. Looks good and fit perfectly

Bob------

If you are able, please accurately measure the ID of the Heartbeat pulley.