Okay...so I impulse bought a spicer eos66-7b only because the price was too good to pass up...just seemed like the thing to do at the time....I also have a divorced GV sitting here that I was going to put on the 86, but am now rethinking the whole thing.

I am seriously thinking of putting the spicer in the 86 and figured dumo the idea out here and get some thoughts....

as far as mounting, a body lift and some fab work will need to be done (and the spicer currently has a sae2 bell)...as far as gearing, the ratios are 7.48, 4.43, 2.76, 1.9, 1.34, 1, .74....reverse is 6.66. I am also thinking that if I go this route I would swap from my 4.10's to 3.73's, howver I dont want to sacrafice the ability to pull up hills...from my initial thoughts even with 3.73's I would end up with a gear lower than my current 1st (and the spicer 2nd would be about the same as my current 1st), as well as much longer legs on the freeway...my concern is losing torque multiplication on the top end...thoughts????

 

This is gonna be a choir as the tranny probably has a standard 2 in input shaft and was designed for a pull type double disc clutch. I'm thinking there is going to be some machine work happening here.

 

i will be picking it up on monday, and will know more about it then....its coming out of a buddies 6bt powered truck....got it for $100 and it was rebuilt less than 10k ago...figure it could be a better option then the gv, and selling the gv could cover the costs of doing the swap

 

What adapter is on the gv and do you have the control box and the switch and wireing.

 

gv is divorced...came out of an old motorhome...I was running it without the electronics...engage it when you want it and shut it down when you dont. Got a local guy here who is thinking about buying it for $1500 (I know its not worth that much, but that number was his idea =) so I figured why not..it will pay for the parts to get the spicer in...if your interested and that falls through I will let you know and we can work something out

 

If you decide to sell that bellhousing, keep me in mind please.....

 

This is all way over my head, but that sounds like an impressive transmission. I hope you can get it to work.

 

I am seriously thinking this may be the way I end up going...gonna tear the whole truck apart anyway, might as well build what I want. My biggest concern now is just the torque multiplication issue using 3.73's..I think I will have enough tranny gear to compensate, but am hioping someone with more "gearing" knowledge than I will chime in
wminmi - drop me a pm with an offer on the bell housing...will more than likley be willing to get rid of it the end of next week.

 

How will you bolt this to the engine? Take the Ford adapter off and use the SAE 3 pattern and get a big truck bellhousing?

 

You're worried about being geared too low? I'd say you could probably get away with 3.08s and still idle a house over, but your driveshaft might be the weak link in the setup. I just can't get over that gear spread. Would be a real fun beast to drive.

I don't know what rear end your truck has or if its 4wd, but at the very least you could probably get away with 3.55 gears and that should give you freeway cruise RPMs close to 2000 depending on your tire height.

 

7.48, 4.43 - lol wow.
you wont even use first and second on the street.
so like David85 says,you have no worries with rear gears.
in fact,you could really do up a MPG test and try scoring a set of 2:50 gears for fun if you could pull this off.
she would have no trouble starting in second gear still lmao.-thats with a load!
you will be starting out in 3rd gear if you use anything lower than a 2:50 gear set i bet.even then,she'd take off in 3rd no problem empty.

 

I would sure be tempted to go with 2:1 or something crazy tall like that, but I have no idea what differential can even accept those gears and still work in an F350. I think the Dana 70 goes as low as 3.07, and the ford sterling stops at 3.08.

 

as far as the axle ratio I am thinking I am going to go with 3.73's (currently 4.10's)...that should put me at 75 turning 2k with 31" tires. My thoughts behind 3.73's is it will give me a solid top end, and my first and second will give me some very low full load take off gears. My biggest concern is the torque multiplication pulling a freeway hill under full load. I am figuing 2500 would be about the sweet spot to control temps etc, and running direct that should put me at 73mph (as in high wind load), and in 5th I would be at about 55.

The weak unit I am sure will be the drive shaft and its parts....with an effective 26.5 ratio in first, it should be pretty easy to break something if I want to.

This one will be my "keep it till I die" dream truck, currently it is a 6.9 NA crew cab dually, but the over time plan is d60 4x4 conversion using rear leafs, remote twin turbos, etc.

as far as moutnting to the motor, yeah it will be sae3, and a custom plate to mount to the spicer...my bigger concern is spline size...being that I have yet to rip into that side of an idi, and I dont know what the eso66 has in it there is a bit of mystery there that has me concerned.

I have a feeling this thing is gonna spend the next year in the garage under the knife...but it will be worth it

 

.74 overdrive would be close to a ZF 6, .72.

Low gear the 7.48 would eat ZF 6 5.79 low gear.

3.73 would be slightly easier on the U joints than 3.55's, but not much.

3.73 would be about 67 at 2000.
3.55 would be about 72 at 2000.

 

you are correct sir...my math was slightly off...I am not sure this is going to be as smooth as I thought...need to get the tranny over here to look at it, from researching it seems some units have an integrated bell housing (the sae2), the other issue is the input shaft should be a 1.25" 10 spline, and I have no idea what the idi has....dave????