[91olds305]

I have a '91 GM B-Body (Olds Custom Cruiser) and I think it has a 700r4 tranny in it. It has 176,000 miles on it and has never been rebuilt. It still runs decent, actually really good considering the miles, but I am not satisfied. Anyways, my question is... What is the difference between a 700r4 and a TH350/400, and for that matter, what is the difference between the 350 and the 400? My guess is that the TH400 has no overdrive because it is the cheapest on <a href="http://www.netgearhead.com." target="_blank">www.netgearhead.com.</a> Since the 700r4 is almost double the price of a TH400 to buy or even get rebuilt, I was wondering if I just could put a TH350/400 in there insead? This is not urgent, my tranny is holding up ok, but i'm just planning for the future!

[Deuce]

700R4........overdrive

Turbo 400......2.48 1st gear ...no overdrive

Turbo350......2.52 1st gear..... no overdrive

A Turbo 400 is a heavier duty transmission than a Turbo 350.

Turbo 400's are larger in size, strenght and lenght. They also soak up more HP while in operation.

[91olds305]

is the 700r4 the only overdrive transmission, and is it electronically controlled in any way? I hate all of that electronic shi...stuff!

[dontmesswiththehombre]

yes the 700r4 has a lot of electric crap and is expensive to rebuild. they are crap unless you spend about 1500 bucks on them.

[91olds305]

are there any good overdrive transmissions that aren't computer controlled?

[willys36@aol.com]

There are years that the 7004R and 200R4 were not computer driven and still had the good parts inside. I think '86-late '88 are the years to look for. The above two are the main ones for GM that fit that criteria. The 200R4 is the poor step child to the faair-haired boy 7004R but it is virtually the same transmission strenghtwise as far as I can tell. Big differences are the 700 is Chevy only while the 200 is usually universal - fits all GM motors. Also the 200 has wider gear ratios (lower first gear) so is better for bigger cars. Finally the polular 700 goes for $$$$ while the less popular 200 can be had for less than half.

Bowtie Overdrives who specialize in these units like them both and gives the 200 as high a grade as the 700.

See my photo album for transmission spotters guide.

[meanmachine666]

check out these folks the make a overdrive add on for the TH350 and TH400

http://www.gearvendors.com/

[57tommy]

hey try bowtie overdrive they are the best

[BOBCRMAN@aol.com]

actually its the 85-88 700Rs that you want to avoid they were still trying to get them to work and did some major revamp internally in 88. the best ones (if there is such a thing) are the ones built post89 up to the change to full computer controll. Don't get me wrong i use them in my own cars but anytime you have a trans that had 5 revisions in the first eight years of production kinda makes you wonder about GMs pre production testing.

[Deuce]

[QUOTE]Originally posted by willys36@aol.com:
[QB]There are years that the 7004R and 200R4 were not computer driven and still had the good parts inside. I think '86-late '88 are the years to look for. The above two are the main ones for GM that fit that criteria. The 200R4 is the poor step child to the faair-haired boy 7004R but it is virtually the same transmission strenghtwise as far as I can tell. Big differences are the 700 is Chevy only while the 200 is usually universal - fits all GM motors. Also the 200 has wider gear ratios (lower first gear) so is better for bigger cars.

Actually the 700 has the lower 1st gear. A 3.06 to 1.

Check this out to see for yourself.

<a href="http://www.tciauto.com/tech_info/gear_ratios.htm" target="_blank">http://www.tciauto.com/tech_info/gear_ratios.htm</a>