Saw a recent article on the Allison conversion kits now offered. Seems like a decent way to go if you e the scratch. Pretty cost prohibitive if I remember right.
On the Ford side, BTS has a strong rep for rebuilding them. I believe he guarantees something like up to 1000 hp. I’ve also read once where he rebuilt clutch packs in a unit someone bought of CLs used for nothing. That’s where I intend to get my 7.3 Tran rebuilt if/when the TC goes south on me.
I ran into a guy that had a late 90’s Super Duty with a wrecker type setup that had a Cummins. He’d picked it up south for $10k and it was pristine. I couldn’t talk him out of it despite a semi serious effort.
I missed an op at a 99 Excursion with 20k miles on it a few years back and I’ve been watching. I would like. Low mileage, clean early Excursion for the stronger 7.3 design they had.
