[Pyrotechnic]

Do you want gas mileage ? These new engines, transmissions, and computers are well matched and tuned systems meant to give lots of power and gas mileage all at once. Most people use the matching electronic transmission because it's a cheap and effective way to get an overdrive transmission at a great price. You basically get the new truck power and driveability in your old truck.

In cases with 4x4 trucks where transfer case drop position, adapters, drive shaft lengths, etc come into play, it's much simpler and cheaper sometimes just to use the existing transmission.

There's nothing wrong with an older transmissions, it just means you lose some of the convenience and efficiency the newer transmission has to offer. If you are just cruising around town or going to the track, you probably aren't concerned about gas mileage or cruising RPM's.

I would ask the junkyard how much they want for the matching transmission. If it's a good deal, it may be worthwhile to go ahead and get it too.