pully sizes 5.0

[greydan]

I've installed a new serpintine belt on my '87 GT. Had to take several home to find one that fit. At first I figured the parts book was wrong??? but it's occured to me (dah) that the thing might have underdrive pullys on it. Trying to find out what size the origional pullies are is like pulling teeth..no one knows and the dealer just walks away.... The local speed shop, won't open the box, to tell me what size the underdrive pullies are either....just smerks.
There isn't a 5.0 in a salvage yard with-in 100 miles of here.
Anyone know the dimensions of either, stock or underdrive?
I was planning on installing a set (Santa Claus) but it appears I might already have them on the thing.

[shovelnose]

Crank 6 3/16" (Dia. Across the front) 18 1/2" around.

W.P. 4 3/4" across the front 14 1/2" around

Alt. 1 5/8" across the front 6 1/8" around.

That's what I just measured with a tape measure for stock pullies.

Hope that helps.

[greydan]

Thanks for the info. Really appreciate it.
Tonight I stood in front of a GT convertable for 1/2hr, in the parking lot of the grocery store....hoping the person would come out. So I could measure his pullies...no lie.
Never came out, figured I looked like I was going to steal the car so I finally left <g>
Thanks again, going out and do some measuring.

[shovelnose]

BTW the easiest way to tell if they are UD is if the crank pully is smaller than the WP.

If the WP is UD it is actually larger than the stock WP pully. So either way the UD crank pully will be smaller.

BTW if they are all UD pullies(not miss-matched) The stock belt should fit. Alot of them are designed this way so you don't need to buy a new belt.

Good luck. If you have the right belt U just remember the size. But I take it your just curious.