I'm getting rid of my S-10, I had the GV unit on it for mpg, was getting 30+mpg. It has the same axle ratio & tire diameter. Overall overdrive ratio is 0.55, so very close to the 6spds. Luckily the S-10 has an electric speedo, dut not a digital dash. I think the tough part will be the c channel mount & any tunnel clearence problems(may have to learn how to sling fiberglass). I know the drive shaft will be very short, hopefully the angles are workable. The body of the GV is close to a 5lbs. coffee can:coffeetime: There are some studs at the rear, a flat spot at the top(to tap for a mounting bolt) to fab up a mount to hook to a shortened c channel. I also may have to change the 700R4, as the GV is meant to bolt to a trans w/ a regular lenghth tail shaft. Mine still has an origanal early 700R4.

GV made one as a bolt in for auto C4's using a shortened C beam.
If you look at the GV site it looks as if they used the Vette tailshaft housing on the O/d unit to retain C beam mount

Thanks vette oz for the tip. I couldn't find a picture of the tail housing, but at the gv site they mention 'requires callaway vette rear tail case assemably', so I e-mailed them some questions, hopefully they can help me out.

Good luck with that bro!:thumbsup3:

No real need to change the trans. You can change the output shaft on the bench for $75 or so. A typical output shaft is worth about $30 (used) and the paper/rubber/metal clad seal kit you would need would run about $35 or so.

I'm getting rid of my S-10, I had the GV unit on it for mpg, was getting 30+mpg. It has the same axle ratio & tire diameter. Overall overdrive ratio is 0.55, so very close to the 6spds. Luckily the S-10 has an electric speedo, dut not a digital dash. I think the tough part will be the c channel mount & any tunnel clearence problems(may have to learn how to sling fiberglass). I know the drive shaft will be very short, hopefully the angles are workable. The body of the GV is close to a 5lbs. coffee can:coffeetime: There are some studs at the rear, a flat spot at the top(to tap for a mounting bolt) to fab up a mount to hook to a shortened c channel. I also may have to change the 700R4, as the GV is meant to bolt to a trans w/ a regular lenghth tail shaft. Mine still has an origanal early 700R4.

I'm getting rid of my S-10, I had the GV unit on it for mpg, was getting 30+mpg. It has the same axle ratio & tire diameter. Overall overdrive ratio is 0.55, so very close to the 6spds. Luckily the S-10 has an electric speedo, dut not a digital dash. I think the tough part will be the c channel mount & any tunnel clearence problems(may have to learn how to sling fiberglass). I know the drive shaft will be very short, hopefully the angles are workable. The body of the GV is close to a 5lbs. coffee can:coffeetime: There are some studs at the rear, a flat spot at the top(to tap for a mounting bolt) to fab up a mount to hook to a shortened c channel. I also may have to change the 700R4, as the GV is meant to bolt to a trans w/ a regular lenghth tail shaft. Mine still has an origanal early 700R4.
how much power is that O.D. rated for?

The GV is said to be rated to 2,000 hp, I've seen them under motorhomes hooked to th400s, so they are tough. The unit has a control box that unlocks the torque converter during engaugement. My experience using it in 1st or 2nd is harsh engaugement, 3rd & 4th engauge smoothly esp. if you lift off the gas while shifting. The slowest I had my engine turning was about 1150rpms, alittle over 50mph. Anything slower & the trans will kick down to 3rd od(which is nearly the same ratio as reg 4th). Turning the engine that slow you have to watch out for spark knock(I used premium & bumped the timing), but she would run that low w/ the a/c & cruise on.
Another reason I'd change to a different 700r4 is driveability, anyone who has driven an early one will know what I'm talking about. The shifting program is really odd, the later units arent always delaying down shifts(like when you turn a corner), & they are a better trans overall. I can't believe mine still drives good, for an early one.

Another reason I'd change to a different 700r4 is driveability, anyone who has driven an early one will know what I'm talking about. The shifting program is really odd & they are a better trans overall.
Pete will tell you about all the post '88 upgrades for durabilty but a good shift kit can do wonders

That is a very strong unit and should work fine, but that 4 inch long drive-shaft I'm not so sure about? Just kidding.
What is the overall length of it?
David Steele

The overall length is 21 1/2'', the adapter is 9''(different lengths for differt trans). The yoke has 32 splines, I think the u-joint is a 1330 series. Those conversion u-joints are pricey. I hope the guy who built my driveshaft can shorten it for me. I'm gonna get it running w/ the 3.07s, then up grade to 3.73s later. I dont know if I'll goto the D44, we'll see what they want for them when the time comes.

The yoke has 32 splines, I think the u-joint is a 1330 series. Those conversion u-joints are pricey.
If yoke is same splines as 32 spline TH400 yoke cheaper to swap to a TH400 yoke that takes Vette 1310 series uni

That conversion is way to $$ for my blood.:abduct:

Check out e-bay, you can find some good deals, the beauty of it is you can get adapters to other trannys, so you can keep it. Plus your not likely to break it unless your making some serious torque. I'm still waiting to hear back from GV about the tailshaft.

Well I had to call the GV company as they didn't answer my e-mail questions, they said I would have to send it in to have the tailhousing conversion done, they want to rebuild the unit too. My gv had a very easy life in my truck, as it only made 150hp & gvw is less than 3,000lbs, so it doesn't need an overhaul. I'm gonna make the brackets to mount it, for the price of the converstion I can buy a nice welder.
I got the exhaust, driveshaft, c-beam, & tail housing down to do a trial fit. It looks like there is alot of room on the driver's side, pass side looks close, but nothing is resting on the unit. I measured from the gv rear seal to the the center of the rear u-joint cap, just over 15''. So the shaft will be around a foot long from the center of each u-joint cap. The tail shaft looks like it was cut down, there is no center dimple(for a lathe to hold it) at all. This is a c4 tranny as there is no convetional tranny mount(just rear of the pan) like there is on regular th700r4s. I wonder if that was a common mod on early c4s. I'm going to make a jig to figure out the mounting locations, I think I'll use 2 shorter bolts at the top & bottom of the c-beam, mock it up in the car then box up the mount to add strength. Any tips or ideas are welcomed

I'm still working on the mount, what a pain. I started out w/ 6''X6'' 3/8 piece of steel, w/ a 3'' hole in the middle. I got it to fit tight over the round tailshaft housing(it's quite beefy), cut a slice in it to expand it enough to get it on. Then I'll weld 2 ears on at the slice so I can use them to slightly pinch the housing, I can also use 2 nuts & a bolt to spread it so it will come off easier. I got a C-beam for 35 bucks, I cut it down close to the length I need. I'm using angle iron at the connection of the plate & c-beam, the dimension is apox. 5'', so I'll weld the pieces of angle iron alittle below 5'' so I can shim the tail up or down to get a good u-joint angle. I have alot of trimmg to do on the plate & figuring out addtional support for it. The picture showing the plate w/ tape on it is what I have to remove. Any one ever use that Craftsman twin cutter? Boy it eats steel quick.:givemebeer.sml:

I had to put this project on hold, to many other things to do this summer. I need to change my phone number:crybaby:.

the overall length is 21 1/2'', the adapter is 9''(different lengths for differt trans). The yoke has 32 splines, i think the u-joint is a 1330 series. Those conversion u-joints are pricey. I hope the guy who built my driveshaft can shorten it for me. I'm gonna get it running w/ the 3.07s, then up grade to 3.73s later. I dont know if i'll goto the d44, we'll see what they want for them when the time comes.

they are really strong units. Low gears shouldn't be a problem with your double overdrive.

Race on!!!