will the transmisson from a 3.8 v6 work on the 4.8L engine

I don't think so, bacause, it's a big diffrence from the 3,8 V6 to the 4,8L V8 engine. Because if it's a V8 it has much more pressure on the transmisson, clutch, etc... So the transmisson from the 3,8L V6 wouldn't last very long.

It will be fine since its the same transmission and can handle up to 700 ft lbs of torque but y not just keep the V8 with the tranny already installed!! Its faster about the same fuel effeciency and much more reliable then those shitty undepowered 3.8!!

listen, working on Fords for 12 years, I've only seen 4R70W/4R100 used. IF it's a seven or eight bolt main and the flywheels will match then maybe. But if your looking to increase fuel milage and save on fuel, maintance is everything, check tire pressure to 32/35psi. But check your miles to how much fuel is in the tank. If a full tank set distance counter and when you fill up again, calculate miles/gallons then you will have your average. Because I average about 22miles per gallon with the original Ford part.

yes it will work they both use 4r70w tranny's

maybe depends on the speed of the tranny and power add ons on the thunderbird.other than that yes. tell me what kind add ons {if any} that u have.