What does it mean to set crossmember at 'center' or 'max position'??

those trans crossmembers slide on the tubes the bolts go through and in some swaps such as a c4 with a 164 tooth bell the trans becomes longer due to the deeper bell and requires the crossmember to be pushed back to its limit on the slides.
 
They've been allowed as of 11/28, per Mike Raburn, just so long as they're not links to your own auctions in the regular discussion forums. You can still only post links to your one time for sale items on eBay in your signature or in the classified sections, as you would have handled sale items in the past. Otherwise, you can post them asking, say "is this LCA better/comparable to MM" or something of that nature, as long as it's related to the discussion, and not an attempt at selling the item.
 
ok...what way was the 'stock' way and suitable for a plain vanilla T5 swap?

Look at the pictures from the top of the crossmembers. The bushings are offset on one of those, and centered on the other, for the reason that Punisher Racing mentioned.

Centered on the bushings:
View attachment 341972

Offset on the bushings (set to max):
View attachment 341975

I will be installing Energy Suspension xmember busings (or at least my friendly machine shop will be). How should I instruct them to install the bushings? Center for a stock application?
 
Stock will be centered. The tubes that stick out of the crossmember should be welded in place. The seller on eBay probably took a grinder to the welds and repositioned the tubes on the offset one.
 
A centered one is what you want, but if you get one that does not have the welded side tubes, you just have to put it up under the car with the trans in place and the bushing in in place and mock it up. Mark the tubes where they need to be welded then take it back out and have it welded. Bam you're done. I had to do this when I swapped my T-5 out for a TKO. Just ground off the tack welds, set the crossmember to max and got them welded again. Good luck.
 
it just takes a few tack welds, dont weld all the way around...2-3 spots with 1/4" long beads on each side is more than enough..and i've never seen a centered one, only offset to one side or another, usually forward..maybe 87+ are different than 79-86, which is what i usually deal with