1970 LS5 Alternator Pulley

[Tom L.]

My alternator pulley that came with the car (likely not the original) is 3.0" in diameter. I picked up a correct and refurbished alternator for the car and the pulley is 3.625" in diameter. Both are machined since its a p/s car. The Quanta belt isn't close with the big pulley in place. Does anyone know what the correct diameter should be? Thanks.

[Dick W.]

Re: 1970 LS5 Alternator Pulley

Three inch is correct for your car

[Tom L.]

Re: 1970 LS5 Alternator Pulley

Thank you very much. You wouldn't happen to know what the correct finish should be? It's not listed in the TIM. The 3" one is cadmium (gold) plated and the larger one is silver zinc plated.

[Dick W.]

Re: 1970 LS5 Alternator Pulley

Most that I have seen are zinc

[Tom R.]

Re: 1970 LS5 Alternator Pulley

My March 17, '70 alternator (1100900) has the 3" pulley and it's zinc plated.

[Tom L.]

Re: 1970 LS5 Alternator Pulley

Thanks guys.

[Marc K.]

Re: 1970 LS5 Alternator Pulley

My March 17, '70 alternator (1100900) has the 3" pulley and it's zinc plated.

Tom Lynam,
Do you have an LS5 car or a 350/350 with the 1100900 alternator? Does yours have p/s or p/b? I have an LS5 with no power options, and I'm always looking for people with similar cars to occasionally bounce questions, and ask for advice or pictures. Thanks.
Marc

[Chris H.]

Re: 1970 LS5 Alternator Pulley

Marc, attached are some photos of my alternator. I have an early LS5, VIN 531 that's a Bowtie car. I only have PB for options. The alternator has the 3 inch pulley and if you squint real hard, you can see a part number on it.

Chris

[Tom L.]

Re: 1970 LS5 Alternator Pulley

Marc,

I have an LS5 convertible 4 speed with p/s and p/b. I'm happy to share information and pictures, but regarding pictures, mine is a restored car. There have been many people on the site, like Tom and Chris, who have provided pictures of their original unrestored cars that have been a tremendous help in my restoration.

Chris, thanks for the pictures.