The MTX-75 transmission has a few issues, but it can hold the torque. The open differential is the apparent weak spot with its spider gears as it tends to be the only geared item to break. I thought mine was going but it turned out to be a bad right front wheel bearing.
I've been running a 3L for over a year and recently turbocharged it. It has held the power fine. I cracked the transmission open two days ago and there was nothing wrong inside of it. The spider gears in the diff look fine.
I am going to put a torsen into it now, should be here in the week!

'monger


Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black