I own an 84 TA.
1)I'm replacing the LG4 305 with a L98 from a 92. I was wondering if the 700R4 from a 92 would also be a direct bolt on, and if the gearing is the same (I noticed on the tech page the OD gear is slightly different).
2)I have a regular differential, 3.23's (or so the equasion tells me). I want to buy a 3.42 or 3.23 limited slip rear end. I know this is a direct option for 84 TA's, but I was wondering if it would be a direct bolt on, or if anything would change ie: yolks, bolt patterns, ect...? Thanks for any replies.

 

Maybe you left some info out or I can't read the codes right.
What transmission do you have now?
All 700's have the same gearing.
If you buy a completely assembled rear end it should bolt right in.
Anything from '82 to '92 should bolt in if you get one with the same type of brakes (drums or discs).
If you want to change brakes too just get the different lines and parking brake cables to go with the new rear.