700R4 Transmission

I'm currently re-building a '67 commando,I have a Buick 1980 3.8L V6 that I've just had built with a RV cam in it and Edelbrock 4 barrel intake. I want to take out the 3 speed manual trans and put in an automatic,at first I was going to use a TH400 ,but upon further research I've found out a Chevy 700R4 should deliver 30% better fuel economy with out being over taxed with 3.73 gears,but WILL NOT bolt up to the Buick engine, has anyone every encountered any thing such as this? I would hate to ditch the Buick 3.8L and go to a Chevy 4.3L after spending so much $$$$ on the Buick 3.8L engine. Any and all input will be much appreciated.......THANX.

 

i used a buick overdrive trans. i think it is called a 200 c. it's almost the same as the 700r4, just the gear ratio is different.any B. O. P.( buick olds pontiac)trans including cadillac will bolt to the buick v-6.you will have to get the adapter for the trans case.

 

Using the adapter sounds like an easy fix.Has anyone used this type adapter to connect a Buick 3.8L to the 700R4 Chevy transmission?Are there any pros,cons or drawbacks? I'm concerned about the torque converter and the flywheel.This almost seems to easy of a fix to my problem,Other than the transfer case adapter and new mount what else might be involved ? I'm aware of the drive shafts,I already have a Dana 44 for the rear and '72 model Dana 30 for the front I know I'll have to have custom shafts made......THANX

 

Another thing to watch out for is the front drive shaft to pan clearance. There is a bulge on passenger side of the pan rail area that will require a small diameter front drive shaft and very careful placement of the transmission engine combination. Also, TV cable (throttle valve cable) adjustment is critical on these transmissions to making them live.
I've seen lots of people use the transdapt BOP to Chev and vice verse adapters in drag racing with good success.... Nickmil

 

Now I'm told by Steve at Advanced Adapters that the 700R4 is about 24 inches long and has to have a tail to transfer case adapter that's at least 6 inches long making the whole outfit with the transfer case about 37 inches overall and that's at least 12 inches longer than whats in there now, not to mention the transfer case levers would now move 12 inches back into the middle of the passenger floorboard and the rear drive shaft not only have to be shortened 12 inches,but the new angle might also cause problems.So that's the end of that...

 

Not realy.
My BIL has one in his MB. with a 327 chevy no less.
If you dont have a lot of lift or plan on extream rock crawling.
I would think it would be fine.
I am sure this has been done over and over.

The Tcase lever in a Commando is too far forward in stock form so maybe not so bad
of a placement.

You will need the small dia. front shaft as stated.
When you mount the motor it should be,
an inch or so off center to driverside to help make room.

Try asking same ???'s at the jeepster commando web site.
forums.off-road.com/jeepster-american-jeepster-club/

It may cost abit more but it would be worth the gas milage and ease of use.
Your on the right track.

http://forums.off-road.com/jeepster-american-jeepster-club/215625-700r4-trans.html

http://forums.off-road.com/jeepster-american-jeepster-club/174084-engine-swap-4-3-700r-4-a.html

 

You can make the adapter out of a piece of 1/8" plate. I used one to mate a small block chevy to a buick th350 and it worked fine.
The buick overdrive trans is the TH200-4R. I think its a little shorter than the 700R4 but i don't know if there are transfer case adapters available.

 

Well ,I decided to check into the 200R4,found it is a direct bolt up,but it's a one piece case, the tail end does not separate, therefore there is not a transfer case adapter. Steve at Advanced Adapters said the simplest and easiest way would be the TH350, it will be a direct bolt up, and if I change the 30 inch tall tires I'm currently running to 33's I should be able to run 60-65 MPH at about 2200 rpm.So this sounds like the best new plan ,unless I here something better from someone else out there in commando land. I would like to thank everyone for their input.......THANX.

 

Hey, it not about your trans, but youre in Altoona, AL? I'll have to add you to the list - there is also "Altuna" in Russia, and I live in Altoona PA. Weird....

 

I would get an adapter to go from the 700R4 pattern to the BOP on your engine. The 700R4 is one of the best choices for an automatic transmission. You get a low 1st gear and and OD. It would be really simple to adapt to the BOP pattern. I would not use the 200, it is not as strong as the 700. Maybe someone knows, but could one use the adapter for the turbo 400?