if the trans is 'screaming' the trans needs some attention
if the engine is screaming at 45, you're not getting into 4th, especially if it does have the 3.38 rear as Longbox suggests .... and no, there isn't a 'kit' for a trans conversion

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature we find it attached to the rest of the world" John Muir
"When we tug a single thing on an old truck, we find it falls off" me
Some TF series details & TF heater pics & Rust-a-holics Unanimous parking lot