I went from M6 to Th400 so can't help you much on all of your questions. I got the same shifter MM did, pro rachet I think...love the way it works as it's just two bumps and you are slowing down at the end of the track. Again I copied MM and fit it under my M6 stuff.
D/S I had standard parts make mine (233-8321) they are off Commerce/Maury-ish. Just got a steel D/S, the thicker one to be safe. Make sure you know whether you have a truck trans (better as lower 1st gear) or not as this will tell you which yoke you need. Truck trans yoke needs a relief cut about 3/4" down the inside of the yoke for it to fully engage into the back of the trans and give you the travel you need for launching (D/S moves in towards tranny when launching, bottoming out is baaad)
I would let Yank or the like tell you what converter you need but know of a guy who seems to be whooping butt with his Th400......better than I did and no turbo....dangit. Truck trans fyi
Definitely definitely get the Tbrake, just plain awesome and helps you get good, consistent launches not to mention faster (usually), just make sure you decide before getting stall as this will change the stall specs....they will make it tighter for use with a tBrake....which again is another benefit for a street car. Also don't do as I did and skimp on the converter. I think you have been around the block long enough to know that though.
Lokar is a good dipstick, make sure you get the longer one...36" I think versus 24" or whatever.....it's just the number at the end of the standard p/n that's different....think it's got a 36 lol
There is a good post on tech about what to do for the A4 to Th400 swap that may have the tuning and fitment answers you need....it's a sticky in the trans forum.
'98 Camaro SS
638rwhp/588rwtq 93 octane w/Meth injection @ 11psi
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