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Discussion Starter #1
What OD trans. Bolts up (4bt in this case) directly using TH 400 adapter, etc?

Ed in CO.
 

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Well I'm no pro on auto's, guess I'm kinda a handshaker馃馃槣 but as a Chevy lover here are the ones that come to mind.
  1. 700r4
  2. 4l60e
  3. 4l80e
  4. 4l85e
  5. 6l80e
  6. 6l90e
A few guys have had ok luck with no.1 but it doesn't take a lot of of torque. No.2 has been proven a waste of time. Main drawback to no.3 is that it only has 4 gears and stock converters seem to be bit problematic behind the 4bt, billet converter seems to be the ticket. Not familiar with no.4 but gm used it behind the Duramax in van applications so it should be up to the task. 5 and 6 are similar with no.6 being beefier at a factory torque rating of 660 ft/lb. They are both 6 speed double over transmissions and to my understanding they use planetary gearsets and clutches like the Allison 1000. Haven't seen anyone run one behind a 4bt but I know they've been used with the 2.8 and 12 valves. I have driven newer Chevys with these transmissions really like how they run especially in tow/haul mode. I think the gear splits would work beautifully with the Cummins powerband.
Mind you all but the 700r4 are fully electronic which is why I drive stick shift. 馃槣

P.S. looks like my reply is as long as your question was short but I'm traveling right now and kinda bored so just my $.02

Glendon
 

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4L80e or 85 but I suspect you need to do some mods and use a lower stall converter because of 4bt peak torq rpm.
 

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We've had a couple guys use the 4L80e on 4bt swaps. So far, those seem to hold up OK. The 700R4 and 4L60e don't have such a good reputation. Don't know if anyone has used any of those higher numbers. Oldroofer and F100 Today are both using the 4L80e.
 

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We've had a couple guys use the 4L80e on 4bt swaps. So far, those seem to hold up OK. The 700R4 and 4L60e don't have such a good reputation. Don't know if anyone has used any of those higher numbers. Oldroofer and F100 Today are both using the 4L80e.
Do you remember what if anything they did to those transmissions other than tune?
 
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