i think im going to stick with the I6 save me the hassle of the swap but if my 6 ever goes out im going to put in a 8 As for how the transmission will do it should be alright unless you do a super 6 build or are planning on racing but for just street use and maybe a little time at the track i would imagine it should be alright with a little extra horsepower. Im not planning on doing anything to mine untill i move on the a T5
If the transmission isn't already dying, you're not going to kill it with the brute power of a 200 I6 no matter how you build it... Check the fluid, make sure it's not burnt, gritty or leaking, (might as well replace the fluid and filter if you don't know when it was last done) and then just run it.
well i do have a leak in the front, from one of the trans lines that goes to the radiator and the cooler.....and i think i have a secondary leak but i dont see it, the underside of my hood is wet after i drive it on the right side by the battery.....but ive looked under there while its running and i dont see anything...... :-/