I have a 1998 crew cab with a 454 with a standard trans I am looking to make it an automatic, my question is what would be a good trans to use? I figure I can use an NON electronically controlled trans because the truck doesn't know if its me shifting or the auto trans. I know there are things I will have to change or add like a trans cooler, jump out or remove the clutch pedal ignition switch, add the linkages for passing gear and a few other things. So I am just looking for suggestions for what kind of tranny to use. Thanks

I dunno...but I'll take that old 5-speed off your hands for ya.

I would go with a 4l80e, you would have to get a stand alone computer to control it, but then you can adjust shift points and what not. It would be more up front but I think in the long run is the best way to go.

Well here's the catch. You said you don't want an electronic transmission, so that limits you to the only non-electronic automatic strong enough to put behind a big block or in any truck heavier than a 1/2 ton, the TH400. So right off the bat you lose overdrive, your gas mileage goes downhill, and your engine RPM's at highway speed will be several hundred higher. You'd also have drama hooking the speedometer up because the majority of TH400's are cable-drive speedo; it's only a very rare few that were electronic speedo, the first few years of OBS some trucks had them. For example I was just posting in another thread an 89 1 ton OBS I'd bought, that's TH400, they didn't start with the 4L80E until 91. As for the passing gear there's no linkage for it, it's electronic on the TH400, you can rig a switch on your throttle linkage or under the pedal that gets triggered at WOT.

Now back to what would actually work best, the 4L80E, and you'd need to get one from a 96 or newer to work in your truck. Get the trans, engine compartment wiring harness, and PCM or have yours reflashed for an automatic. You'll also need the steering column, shifter cable, and a radiator with the cooler built in - an external cooler alone won't cut it esp on a big truck. Best setup is radiator cooler + external cooler, the way the factory did it.

You will probably also need to remove the pilot bushing in your crankshaft so the "button" on the front of the torque converter doesn't bottom out on it and not seat properly. Some people just drive them further in but to me that's a hack and if you ever want to use a standard with that engine later you may have to have the thing machined out and a new bushing put in. Lisle makes a sweet tool for removing the bushing and it's not expensive.

Richard

Rich's knowledge blows me away every time.

Now wait a minute! The question was

And Rich said

and I said the same thing before him

so how come I don't get no props?

Cuz you didn't beat him up with a bunch of pointless details.

Richard