My '83 E100 van came with a code "14" rear axle which I see listed as a 3.00 ratio, and I need to up this to at least a 3.55 for towing. My rear end is a 9", but most of the suitable donors I've found at the local salvage yard are later models with the 8.8" rear end. What year/ model 8.8" will bolt up in place of the 9"? I've been told most vans made up till '91 would have the same shock mount locations, etc, anyone know if this is correct?
Second option is to keep my rear end and swap out the 3rd member from another 9" with the appropriate gearset already in place [if I can find one]. Would this be easier than swapping out the whole rear end?
I'm pretty sure that the chassis up to 91 were the same, so the 8.8 should bolt right in, I would just check the spring mounting pad width and u-joint type. The driveshaft length may vary slightly also due to diff size.
My suggestion would be to look for a new 3rd member, maybe lower gears. There are a few companies (Jeff's Bronco Graveyard) that make rebuilt 3rd members for the 9", but they are kind of pricey. You could probably find one used if you look hard enough.
Or, just buy some gears and have a drivetrain shop swap them out, or do it yourself.
Big thing here is a combo of time and $$. Would prefer to find a 3rd member w/ appropriate gears to swap out as this would be the easiest overall swap, but finding a 9" with a decent ratio has proven a bit tough. If I had a wad of cash just I'd buy a new ring & pinion and have it installed. Unfortunately that's not the case.
You can set ebay up to email you whenever a new item in your keyword search turns up...I've seen plenty of complete 9" centers show up there ready to go. 3.55:1 is pretty popular, I can't see you waiting over a couple of months to find one that ends under $300.
Not going to "ebay" a pumpkin, shipping would eat you alive. My local pick-ur-part lot sells pumpkins for ~$49, complete rear ends for ~$59. If I were going to do the eBay thing would just get a gearset and pay a local shop to set it up.
Yeah, shipping is a &$^$(, I spent $110 on shipping for the rear end I bought (full rear with axles though)...I wouldn't have done it except for the 31 Spline Torsen differential and nodular case that attracted me. There is a serious pucker factor when your waiting to see if you got junk or not when the price gets up there. I even live close to a pick-a-part, but I've just been getting used to parts showing up on my doorstep. For some reason my pick-a-part doesn't seem to have many 9" rears anymore. They must get picked through during the week.
About half the 9 inchers in trucks and vans are either stripped of their pumpkin or in some state of disassembly, most of the intact ones are 3.0 or 2.75 [no one wants 'em]. If a 3.50 9" doesn't turn up in the next week I'll probably do the rear end swap for one of the early 90's 8.8's which are plentiful.