Hi, I am in the process of converting my 1987 Formula 305 engine from belt to serpentine. I have all the brackets from a 1989 formula. All the brackets fit perfectly. I was not able to get the damper pulley, so I bought a new GM 6 rib pulley, part number - 10085754 I installed it today and it appears to be too short, at least by 1/2 inch. It does not line up with the other pulleys

Has anyone who has done this conversion had this problem. If so, how did you remedy it? I assume if all else fails, I can put spacers behind the pulley to bring it out.

Your thoughts anyone.

Thanks,

Louis

Don't add spacers behind the pulley, I suspect you have the wrong pully, give me a few minutes, I have the one off of the '89 here, I'll mesure it and post up for you to compare.

Thanks Mike, appreciate it.

Louis

10055879 should be the one you need.

The GMPP serpentine kit is the thirdgen setup, you can usually find the kit contents list with part numbers with a Google search.

https://paceperformance.com/i-625526...-with-air.html

So my pulley is about 3 1/4 inch, laying rib side down, tape measure in the hole to the mounting face. Let me know what your's is. Could be possible a different HB is needed, but I don't think so.


Edit:

Looks like Drew has ya covered!

From Summit's applications list for 10085754, it sounds like the pulley you have is the one that fits trucks from 87-2003, like 4.3L S-trucks, Astro vans, etc, ie the other serpentine setup. The car setup is different.

Drew, Mike...thanks for your help. Mike, what is the part number on the pulley that you have?

Louis

GM says....

10055879 AAD

See, Drew had ya covered!

Yeah, but I cheated using Google. If I'd walked down the hall and grabbed the pulley off the shelf, you would have beat me to the reply. I didn't even think to look at the number on a pulley.

Lol. Luckily the beer fridge is in the shop, just outside the door. Damned, if Summit would deliver soon, I could forgo a few for a bit