if you look at this web they have neck spaced pups and brigde spaced pups...the 490R is the neck one and the 490T is the trembucker....i think gibsons pups R and T terms means regular and trem-spaced...go for the trembucker version of the pup you prefer
it wouldnt matter what the r and t stand for cause rhythm is always gonna be regular spaced cause rythem is the neck and treble is bridge so it can be f spaced if needed.
If you say so. Standard spaced pickups fit just fine in my 2000 LP Standard. I grabbed a trem spaced pup out of the closet to double check and the pole pieces are spaced way to wide for the LP.
Its true Gibson began making pickups that had different spacing for each postion but they have never made instruments (LP's at least) with the old fender/Floyd Rose spacing the Trembuckers were designed for.