Transmission Advice needed

[83burban]

Well the 800 dollar rebuild for the 700r4 went out after about a year and half. Not too pissed becuase it lasted longer than I thought it would and it worked pretty well. So heres the dilemma:

I use my suburban to tow and haul people alot, it has a mild 350 in it now that will eventually be upgraded to a 383 or possibly bigger. So whatever trans I get will have to be beefed up accordingly. I have 3.42 gears with 31" tires.

I have done research and concluded the hughes performance is my best choice, going with one of their heavy dity towing kits with the converter and cooler, but I don't know which is best - I would love some real world experience here too.

Should I go with another 700r4 built for towing?
Or should I go with a 350 built for towing and add the gear vendors option?

Keep in mind that I know the gear vendors will cost more (with the unit and teh driveshat mods), but if you could pick one of the 2 which would it be. I'd really only like to have to deal with the trans once and am leaning towards the 350 simply beacuse I WILL be hopping up the motor eventually.

Thanks guys

[Mr.Chevy4x4]

The turbo 350 is really no stronger than the 700r4. Put a good sun shell, clutches, and servo in it, and make sure the planetaries are in good shape. When you put it back together add half a quart of motorcraft synthetic 5w20 motor oil along with the trans fluid. The planetaries are the wear prone hard part and regular trans fluid doesn't have good lubricating properties. The small amount of motor oil will help the lubricity. Should last for many trouble free miles.

[bikes&bowties]

th400 w/ gear vendors is my vote

[benoit454]

700r4 has a lower first gear so it would better for take off, esp towing. I personally hate a 700 and would take a 350 anydayd but in your case I think 700r4 or just forget the overdrive junk. A 700 could be built up good and should work great. Any transmission can be kinda weak, and any can be made to work behind anything pretty much, alot of upgrades for 700's now.

But 3.42's and a 31 inch tire? that's kind of a highway setup anyways, I got that setup in my 88 with a th350 and it's slow on get up and go, but flys down the highway with hardly any rpms. I think I'd go with like 3.73's or 4.10's and do an overdrive.

[83burban]

Thanks guys. I do plan on eventually changing teh rear-end to a 12 bolt with posi and 3.73 gears.

Even with a built 700 you still can't tow in overdrive (but you can with the th350 and gearvendors)

Also, the wide gap between gears on the 700 makes the engine climb up in rpm before it shift, whereas the th350 with a GV would do a better job keeping the engine in the powerband even when towing.

I know it sounds like I'm talking myelf into the GV unit, but I would really like some real world advice.

[cableguy0]

The only thing your going to accomplish with the gear vendors is a lower rpm. Gains in mpg will be very minimal because of the added parasitic drag. With what you will spend to get a th350 and gear vendors You would be way ahead of the game just getting a 4l80e and the standalone controller to make it work. Its basically a th400 with an overdrive. Its very strong and will hold up to towing. The standalone controller is about 1000 bucks. I would assume you can get a trans and converter for under 1000 said and done. That put you cheaper than what just a gear vendors unit alone would cost ya.

[Slonaker]

Originally Posted by bikes&bowties

th400 w/ gear vendors is my vote

Same here if you plan to do much towing.

Slonaker

[83burban]

I don't want to put a new model trans in, so all the 4Lxx's are out of the question. The choice is really between the 350 with a gv or a 700r4.

I don't tow all the time, but the car is heavy and has alot of gear in it constantly, thats why I'm looking at a beefed up 350 and not a 400. 400's take more power to get going and don;t have as steep of a first gear as the 350

[cableguy0]

The 400 and 350 first gear are almost identical. Your talking 2.48 of the th400 compared to 2.52 with th350 not even close to enough to be noticeable. The th400 can also be changed to a 2.75 first gear with a planetary set.

[gchemist]

4L80E with a electronic controller. What is the max towing weight?
http://www.transmissioncenter.net/4l80e.htm

[old Rusty C10]

ditch em both and get the th400 and dont worry about a thing

[bMr]

'83Burban, you already know the answer! LOL

Full disclosure: I've yet to do this yet so can't pass along results but I was at the same cross-roads and these were the conclusions I reached:

I want to do this once. No matter what I do to the engine, stroked, carb, or FI, this choice needs to work well with and handle the power of them all.
I want it reliable and something I don't have to think about while traveling and towing.
I want something that a typical mechanic could diagnose if problems arose while away from home.

I won't tell you what to do, but I've decided on a TH350 + GV. 6 Speeds and the ability to tow in overdrive? Yes please!