View Full Version : 10% belt length???

02-28-2005, 07:35 PM
I went to the parts store today to pick up a shorter belt to run with my 10% pulley. I had read on here in several threads that it's a 39' belt or 390. They didn't have one that size in stock and his warehouse didn't have one either. They did have one they said was 39.2" inches 392. Will this one work? I'm suppose to pick it up in the morning.


02-28-2005, 07:43 PM
Hey David,
With that 10% pulley I sent you, the 392 should work just fine....anything between a 390-393 will work.

02-28-2005, 07:46 PM
I got tied up this weekend and wasn't able to get to it and now I'm close, if I can get the right belt. I should be able to get the 5% in the mail to you tomorrow. :D

By the way, how's that baby doing?

02-28-2005, 08:15 PM
what I did for another guy was use the belt he had and put a bigger tensioner pulley on it instead of the small one thats close to the jackshaft. It works fine I had to do it for my 5% too

Joisey Jim
03-01-2005, 02:34 PM
Generally if you are running a 10% overdrive pulley & stock tensioner pulleys you'll need a shorter 390 belt (normally coded 80390 - 8 being the number of ribs and 390 the length). If you have the replacement Cobra type tensioner pulleys, then because the SC one is larger than stock, you can usually manage with the stock belt (typically 392 on '89-93 and 393 on '94-95. There is going to be some minor variation in length between manufacturers anyway; some people like the Gates belts, but personally I like the Dayco Poly-Cog, because the ribs are pre-cut - so no need to worry about the belt cracking & it wraps much tighter around small diameter pulleys like a 10% SC.

03-01-2005, 06:00 PM
I don't plan on changing the pulley again any time soon. More work than I thought it would be. Doing the 5% seemed much easier. I had taken the top radiator hose loose to give myself a little more room to work. While pulling the tensioner back, my wrench slipped off and I got the end of the water neck pipe with my ring finger, just above my ring. OUCH, $%%#%$ %%$#^%# ^%$#$, YOU GET THE PICTURE. But it's on there and unless I have a problem, it's going to stay. The belt I put on is a Goodyear Gatorback 4080392

Funny thing is on the back of the box the belt came in, it shows the belt routing and say it's for a Ford 3.8L. :eek: :D

Chris, I'll get the 5% in the mail in the morning. Right now, I'm gonna go stop the bleeding and put a bandaid on my finger.

I'll have to wait till I'm going to work tonight to see how it does.

03-02-2005, 10:01 AM
Right now, I'm gonna go stop the bleeding and put a bandaid on my finger.

Nothing like mixing antifreeze, oil, and blood...... :mad:

Anyway, you didn't need that knuckle...... :D

Seems like most repairs done to these cars requires a Dr's appointment and a pint of blood......

03-08-2005, 05:38 PM
I thought this was interesting. http://www.autozone.com has the gatorback belt listed above as being the belt for our cars for jackshaft to sc. I think with the stock pulley on there, you'd have a fight getting that belt to fit. It was hard enough with the 10% pulley. What is the stock length of that belt?

03-09-2005, 06:00 PM
Nothing like mixing antifreeze, oil, and blood......

I'm sure they have a technical term for this condition in the medical field. :D :p