I would really like a turbo 400 in my truck

Jimmyperf400 said:

I built my 700r4 with every after market performance part they make and I've towed a 10 thousand pound excavator with the 1990 gmc jimmy its in and I've never had any issues. But up to you you know what you want.

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alot of people refuse to hear stuff like this from a 700R4.
It would not not cost alot to have one built correctly. You also dont need expensive parts.
They just have a bad name cause people dont know how to adjust the TV cable.

Jakewalter, Talk to Nicks Transmissions here on the forum. He can do anything you want.

Late to the party...

If swapping out a 700/208, a 400/208 combo is a direct replacement. Shafts will still fit. If you don't want to replace the transfer case, you'll need a 32 spline input for your current 208.

While I don't tend to be a fan of the 700r4, a properly built one is perfectly capable of hauling around a 4k load on a regular basis.

What gear ratio is in the axles?

jakewalter said:

I have a 85 K20 that I built up to haul our 3500 pound pickup camper.

It currently has a pretty healthy big block that I built for torque.

The transmission is a 700R4 and a 208 transfer case.

While on vacation a couple of weeks ago the transmission started slipping and I lost reverse.

I never use the overdrive and as for mileage I threw my pencil away a long time ago.

Other than a TH400 out of a 4wd what else would I need?

I would really appreciate any input that you guys could share with me.

I need to apologize.

The guy that rebuilt my transfer case said that it is a 208 not a 203.

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There’s a dude in the next thread down with a turbo 400 looking for a 700r4 setup. You two should spend the weekend together.

The first gear ratio of a 700r4 is a steep 3.06, the TH400 and 350 are right at is 2.52, depending on where you get your info. 4L80e are relative cheap to buy, and upgrade. Friend with a 700r4 in a 650 horse gen 1 427 cost him over 4000. I have ridden in that car and did not like the big jump to second gear, 4.11 rear gears.
As mentioned above, 400, and 4l80e have 32 spline output, and as stated previously are fairly easy to install. However my 205 needed the large bearing in the TC, so it needed machining. You may need your driveshaft modified. The 4l80e needs a controller My favorite: https://www.usshift.com/usq4rd.shtml. I say this so that you can be aware of some options I have tried/driven/had personal experience with. Bucket says that they are a direct . Study!!! I have a 700r4 that I could put behind my 6.2l Detroit diesel for cheap, however long term reliability for me is hands down the 4l80e. Mine has 45000 miles late model with all the upgrades 450 bucks. I will modify my drive line and tc myself, (journeyman machinist). bought the tail shaft adapter from Trans Dap couple hundred. All told less then 2000, but should last a lifetime. I will use the same trans behind the modified LQ4, or Modded 454, havn't decided which motor.