My 67 Vista Cruiser has a long tail shaft Turbo 400. I would like to put an overdrive trans in the car but I dont know if the 7004R or 200-4R was available with a long tail shaft. I dont know if I can use a longer driveshaft, I already have a very long driveshaft and there is no center support bearing. As most of you know the 67 Vista is about 5 inches longer than a comparable "A" body car and that includes the wheel base so I dont know if a longer driveshaft will work without the "whipping" motion at higher speeds. I do drive this car a lot and would like to get better than 12mpg's. I have 3.08 gears with a 78 403 engine in the car, I know they arent known for getting good mileage but I would like to get as good as I can.
Anyone have an opinion?

 

Just keep in mind just how much gas you can buy for the amount it takes to put in an OD transmission. Lets just say you have $2000 in converting to an OD. If you gain 3 MPG, it will take a LONG time to pay for $2000. It will likely be more than $2000 to put an OD in it and most OD do not gain more than 3 MPG. The best place for an OD is if you run 3.73 or lower gears, not MPG.

 

You are correct to be concerned about the potential for driveshaft failure as the length increases.

Without a long tailshaft transmission, your driveshaft would be about 2 or 3 inches longer. One of our members with a Vista Cruiser had his custom driveshaft fail. Fortunately it was on a chassis dyno, so the damage was less than it might have been if it were on the highway.

To be confident in changing to a longer driveshaft, contact a well-respected driveshaft maker (in my build, I used Denny’s Driveshaft, a specialist in high-speed, high-RPM driveshafts). Before quoting you, they will ask you for your maximum driveshaft RPM and will give you instructions on how to measure the length of a new driveshaft.

If they quote a larger diameter, come back to CO for suggestions on how to measure for radial clearance.

Good luck.

 

I believe a 4l80e is within an inch or so of a long tail 400.. better choice than the 700/200 anyway.

 

How about a Gear Vendors Overdrive unit? They are quite popular to bolt on the back of a non-overdrive trans like a THM-400. My friends use them allot even on cars they race on a regular basis. If you add one of those units---the driveshaft will then become shorter which helps your problem. Just a thought.....

https://gearvendors.com/index.html/

 

Unless you’re willing to put deeper gears in the rearend, I’d hold off on overdrive. With 3.08 gears, your car should glide very comfortably as is.

As others mentioned, it will take a lot of fuel savings to pay for an overdrive swap. And overdrive with 3.08 gears will have the engine loafing just above idle at typical highway speeds. In fact, the engine might fall below its torque curve and get basically the same fuel mileage as it does now.

Now, if the transmission needed rebuilt anyway, that might swing the discussion more towards justifying an overdrive swap.

 

Really? With the converter locked up, with 3.08 gears, I run 1750 rpm at 60 mph with my 4L80E and a 28" tall tire. And yes, go 4L80E for a long transmission. It is a massive and a long transmission compared to a TH350 or 2004R. You either have to manually shift it or add a TPS and a transmission controller to automatically shift gears.

 

I swapped my TH400 for a 200-4R while running 3.08s and went from 15 mpg to 20 mpg. So ignore all those saying there's no improvement. There very much is even with those gears. I also have no idea why people on an Oldsmobile forum are so hell bent on revving the crap out of their engines on the freeway. The one thing an Olds motor is good at is low RPM power...take advantage of it.

As for the length issue, I'd go with the gear vendors unit. TH400s are one of the few automatic transmissions worth a damn, the gear vendors is pretty much bulletproof, and you'd end up with a shorter driveshaft.

 

Even my cammed 455 is happy during 60 mph cruising at 1525 rpm; however, I do have to use 5th gear--2275 rpm--for 5% and steeper hills. Your stock 400 should be more flexible turning at 225 rpm higher than my setup.

 

Toocool, you have a great fleet of cars with diverse capabilities. The right approach for your Vista Cruiser will depend on budget, what you use the wagon for, how that 403 is built, and what kind of performance you want when not on the highway. Nobody has mentioned swapping the 3.08 gears out for real highway gears but that might work for you depending on your goals and the build on your 403.

Didn't many of those 403s come with 2.41 and 2.56 gears during the gas crisis years? Even 403s in some Trans Am Bandits came from the factory with small cams and a tune to match the 2.41 or 2.56 gears to produce low rpm torque and maximum mileage. Your quickest and cheapest path to better mileage is a carrier swap and some highway gears for whatever rear end you have in there. You may not be able to spin the tires anymore but you will get mileage as good as any OD options at a fraction of the cost. If highway gears will work for you reach out to Jim at JDRace.com, aka Monzaz on this site, he can get you the gears you need. You will have enough saved versus an OD retrofit to splurge on some other upgrade to the fun fleet.

I have a 67 Vista Cruiser as well and have installed the Gear Vendor OD and was happy with the results, but even with a used GV OD it cost plenty and was a huge project. You will have to start with a short tail TH400. The combo of the long tail plus GV would push the unit so far rearward that you would have to cut a huge chunk of the driveshaft tunnel out to make the assembly fit. The GV plus short tail TH400 will shorten your OEM driveshaft by many inches. With the short tail TH400 plus GV you will still need to do some pounding to open up clearance in the tunnel to keep driveshaft angles in limits. I recall it needed 1/2 inch clearance over nearly a square foot of area. The 4L80E sounds interesting but at the time I did my OD install it was going to cost at least twice as much with the 4L80E versus the low hour, used GV unit.

 

If you need a longer driveshaft you could always have one made with a cardan joint. That's what Oldsmobile did on my 71 98.

 

The Cardan shaft may be the ticket, that can give me the length that I need.

 

Changing the rear gears is not an issue, thats one of the things that I do. I just dont want it to lug down and have no power. I just would have to track down a 2 series carrier for a 10 bolt Chevelle rear end.

 

You will need more than a stock build in a 700R4 and 2004R. Consider that into the cost. The 700R4 is longer and maybe slightly stronger in stock form than the 2004R. I have killed two 2004R and a 4L60E, an electronic 700R4 behind Olds 350's and a 403. The 2004R has better gearing spread and a tiny bit better OD. More places build the 700R4/4L60E but only a few actually build ones that last behind any power. My only issue installing the 4L80E in my 70 was the center cooling lines, they needed floor clearance, earlier models have regular cooling lines position. The rest just barely fit. I am using the $50 Amazon plug in, manual shift controller. The only thing that doesn't work is the lock up torque converter control. So I currently run at 2000 rpm at 60 mph. Part of the reason I went with the later trans was slighty stronger and this trans from a van with a 6L comes, which was a low mile reman, is the factory high stall converter. I saw mid 2000's online, mine flashes at 2100 rpm, not bad. Good luck, no easy solution. I had one of those Double Cardan joints fail on the front drive shaft of my 2000 Dakota 4x4. The front drive shaft was slapping around underneath. Had to go to Napa to even find one. It is a weird set up.

 

Understandable. For what its worth your mileage is very good...

1967 Vista 250hp/330 with TH400 mpg rating 11.3 avg ( 4050 lbs curb)
1967 Vista 320hp/330 with TH400 mpg rating 11.0 avg ( 4061 lbs curb)
1977 442 185hp/403 with TH400 mpg rating 11.9 avg ( 3887 lbs curb)

 

Last summer I swapped a 700 into my 455 powered 81 GMC 1/2 pickup. It had 3.08 gears. I didn’t like how it drove at all. Part of the problem might have been the core I used to build the trans, it came out of a wrecked cop car with the 9C1 option. It had the governor with the lightweight windows, the oil baffles on the planetary gearsets, and the more aggressive valve body. It didn’t want to go into overdrive until almost 60mph, and would fall out of overdrive around 50. I played around with different governors, tv cable setups, nothing made much difference, until I swapped in 3.73s. Night and day difference.

I think 3.08 gears were the absolute highest gears you could get from the factory with an overdrive trans. And even then only lighter vehicles like S-10 trucks.

 

One reason this is an issue is this car with the original but very tired HC 330 would get a good 15mpg or a little better, of course it did require premium fuel which was hard to find in a lot of places out west and required "Boostane", a real octane booster at almost $10.00 a bottle for every tank of gas.

 

Put a corvette servo in, a wide 2-4 band, upgrade the 3-4 clutch pack, install the later model input sprag, and upgrade the boost valves. While that SOUNDS like a lot of parts, most of it is stuff that’s replaced anyway during a good overhaul. Instead of stock replacement stuff, you upgrade to the same internals as used in the 4l70E. At most, a couple hundred bucks over the cost of stock replacement parts.

The 2004R is an ideal swap, but parts are very hard to come by. There are a few places that specialize in upgraded internals.

 

Yes, for a 700R4 and 2004R, a 3.08 is borderline too low. I had 3.73 gears and tall 265/75R16 tires with the 4L60E for the same 1750 rpm at 60 mph. My 88 Cutlass came factory with a 2004R and a 2.56 open 7.5" POS. Even without the lockup working, yeah like 1500 rpm at 60 with the short factory 14" tires. I upgraded to 3.42 gears. It shaved .6 of the 1/8 mile and would burn of both tires with the no slip. The 4L80E less aggressive .75 OD can get away with the 3.08 because of it. He will have the same or better performance if he selects a converter like I did with a 2000+ stall.

 

Both those trans need upgrades to live behind power. So many failures in the 3/4 clutch packs in trucks. I also saw the weak reverse in my 4L60E. Also had that in a TH350, an over rated trans as well. The best shifting 2004R required the.555" boost valve, hit 215 psi in foward gears. Also the Transgo shift kit and servo. Also a deep pan and bottom feed early 4L60E filter were another improvement. I only had to do stator in this trans due to wear.

 

The biggest flaw with the 700/4L60E transmission is as soon as you build enough frictions into it, and get the hydraulics right to properly clamp the upgraded frictions, you start breaking hard parts. And by the time you spend the money for upgraded internals, that money would be far better spent on a 4l80.

The 200R4 is a weaker trans from the start, however all the weak factory parts are easily upgraded with aftermarket stuff.

I build alot of performance transmissions. It’s been my experience the 700 is pretty reliable up to around 500hp with common factory upgrades. I have yet to have anyone ever bite the bullet for the expensive aftermarket upgraded parts. As far as I’m concerned, the ONLY way I’d ever consider buying all the fancy aftermarket Sonnax parts is if a 4l80 just won’t fit. A corvette with the rear mounted transmission is a perfect example.

 

4l80 cores are all over marketplace for cheap. I've seen a few listed for $100 bucks and a supposedly good take out for 500. Thats where i would start.

 

Probably more like $4000-$5000 when all is said and done. Maybe even more.

 

Yeah up here, $5000 sounds about right. A member on here got a performance 2004R build probably 3 years back in Winnipeg, he was $4000+. Good used 4L80E are $700 to $1000 here, 2WD are rare up here and have a higher price. I paid $1000 for low mile GM reman 4L80E. With the Transdapt bell housing adapter, Transgo shift kit, Amazon manual shift module, steel pan with drain plug, around $1500. I had a TCI Fastgate shifter. Otherwise add in an aftermarket shifter in the cost. No way the stock column will work with big distance between Park and Reverse on this trans without significant fabrication.

 

You could always scrounge around at salvage yards looking for a used Gear Vendors unit. My coworker found one in the salvage yard for the C6 in his 71 Mercury Cougar. The problem is that if you found one I don't think Gear Vendors offers aftermarket parts for their units. My coworker said he had to source an adapter plate separately.

Try this website and a national search if you want to find one used. I'd start by searching for full-sized pickups & vans from the 80s & 90s that are near you and widen your search from there.

http://www.car-part.com/

Here's some good info on buying a used Gear Vendors unit. I've ordered parts from this guy before for my 86 Ford F250. A+ for price and shipping.

https://www.nickpisca.com/diesel/eng...dor-overdrive/

This is where my coworker ordered his used adapter plate.

https://norcaltransmissionparts.com/gear-vendors.html

 

If you do buy the 4l80e, try to find one from a van with the longer splined shaft. I put a truck 4l80e in my '65 Skylark and it works well, but I had to buy a counter bored yoke. The counter bored yoke works, but full spline engagement is better.