84 Turbo 400 to 4L80 1995 chevy 2wd

[Low_Bridge]

84 Turbo 400 to 4L80 1995 chevy 2wd

My 84 Motor home has a Turbo 400 hundred. this thing has got to have 4;56's or better in it.

So I find this good 4l80 out of a 2500 6.5 pick up. what will I encounter to make the change - first question will it bolt up to my 6.2 & use the Tourque converter from the 4l80 . Thanks $250

Thank

PS how much might this drop the rpms at highway?

[DmaxMaverick]

Physically, it'll bolt up with no problem. Use the 4L80E torque converter. You will likely have to "adjust" the driveshaft length, or match one.

Electronics/electrics, on the other hand, is the catch. You will need a controller and some other (simple) accommodations.

[Low_Bridge]

that's what I thought-

He said it works fine they had a starter bolt problem with the truck-

Aren't these usually expensive to have rebuilt? or freshened up?

I'm thinking I should have it gone through before I put her in?

Thanks $250 is a good price even as a core converter & yoke .. I think

[DmaxMaverick]

$250 is an excellent price. Cores range from $500-$1,000, and more. They can be costly to repair, but a "refresh" isn't too bad. Much depends on its current condition. If it works well now, it may not need anything more than a service (fluid flush, filter), and continued regular service (if it ain't broke, don't fix it). Consult a local shop, or get real friendly with a repair manual if you need more than that.

To answer the OD question, multiply your current RPM by .75 to calculate the RPM after. Also take into consideration the lock-up converter. It will lower it further under load during lock-up (typically 100-300 RPM, compared to the 400), and compression braking (if configured to not unlock) will be much more effective.

[Low_Bridge]

Is there anything else I should try & grab off the donor truck for the conversion?

Thanks

[DmaxMaverick]

Not much, really, being an EFI model. If the donor is a wreck, grab the shifter cable, fluid cooler and lines, and electrical connectors. The cooler lines and cable won't fit your rig, but you'll need them for adaptation (or spend big bucks later). You'll probably have to splice in the electrical, and having the connectors handy will help.

[Low_Bridge]

Actually it is a diesel:

"1995 chevy 6.5 diesel parts"

[DmaxMaverick]

Actually it is a diesel:

"1995 chevy 6.5 diesel parts"

Doesn't matter. It's an Electronic Fuel Injection Diesel. Yours is MFI (M=mechanical), with NO electric/electronic tranny control (should only be a vacuum valve on the pump to operate the modulator, and mechanical linkage to the tranny). Different animals, electrically. The 92/93 6.5L is MFI, and would be easier to adapt. The parts you need to cross over aren't on your donor. The 1994 and later models have a PCM controlled 4L80E. Prior to that, throttle position was relayed by a TPS (Throttle Position Sensor) mounted to the injection pump throttle (you'll need one, to tell the tranny controller what your foot is doing with the skinny pedal). EFI's have no mechanical throttle control (cable or throttle external to the pump), AKA: Fly-by-wire.