first s13 help with mods

[S13drifthatch]

Hey I just picked up my first s13 and first 240 for that matter.
Whats the first things I should do?
its got some work done nothing major.
its a 91 with the ka24de.

for the sake of my question ill list a few of the things I know this car has so its not suggested,

rebuilt motor
energy bushings, all replaced.
egr valve delete. Prolly the first thing to go in my opinion
tokico blues all around with no name springs. also on the top of the list
CAI
decent rims not to concerned about those yet.
exhaust

it seems like the trans or the diff is about to go.
whining after letting off the gas at freeway speeds. goes away with acceleration.
also kinda knocks as i put it into gear not hard to put into just kinda spanks a little when put in. lol cant rerally describe it any other way.
doesnt like reverse as in it grinds in the diff or something when reversing sometimes.

So yeah any ideas would be helpful as to what I should do first besides suspension.
also if anyones got a decent trans lying around.
im in san diego ca

thanks in advance for replies.

[TheRealSy90]

Is the differential welded? It sounds like the lash is out of spec as far as the whining goes.

Future mods really depend on what you want to do with the car.

[S13drifthatch]

No I'm pretty sure it's not welded.
I'll look into getting it welded though. There's a place around here that does it pretty cheap

[Renelovesnike]

No I'm pretty sure it's not welded.
I'll look into getting it welded though. There's a place around here that does it pretty cheap

id also look into the condition of the subframe bushings since there usually shot out for a car of its age*

its usually the front two that go out so youd hear like a knocking or the subframe literaly slap the underbody*

wouldnt hurt to look into/checkout.

[S13drifthatch]

I'm pretty sure he had said those had been replaced.
I've got auto class on Thursday and the have a nice lift there. So I will be inspecting the crap out of it once I get it in there.