JCushing

this isnt really related to the other tranny post so ill just make my own cause it has me thinking. does the casing itself matter (gsr/ls)? i was thinkin for my future turbo car that a gsr 3rd and 4th gear would be nice in my ls tranny. this would make gears 1-4 identical to a gsr and the nice high ls fith for highway cruising. this will also leave me with the 4.26 ls fd too which wont be as quick as the gsr tranny but still have closer gear ratios. how does this sound or should i just get the 4.40 or 4.75 fds or should i just get a gsr tranny and swap that. also if i hybridize the ls tranny where would be a good place to get gears and fds? are they interchangeable (could i use an itr or gsr 4.40 fd) and will the gears just swap out (im thinkin yes)

ideas thoughts sugestions welcome. btw this will be for b18b stock redline and 8-9 psi off a t3 or t3/4 mostly street driven but sometimes highway and prolly gonna get 195-50-15 s-03's since there on sale. (that should be anything that would matter bout my car relevant to this post)

JCushing

damn my question got bumped way down. hmm other thoughts are that now when i redline 2nd and shift into 3rd im at 4800 rpms. would haing lower gears totaly eliminate 3rd gear?