8.25 w/ 2/45:1 Woes and Confusion

So, I know I have an 8.25 with 2.45:1 gears.#-o
I would like to keep this cheap.
Just a toy that my sons and I take to the local track and cruise occasionally.
What I need to know, is what I need to do to get a limited slip with 3.55's or better in it.
I have been reading and reading and reading.
Pre 97 Jeep Cherokee....
Dodge Dakota...
Case break above/below 2.56...

Now for the info.
'75 Dart 4 door that started life as a cop car.
318 w/ 360 heads, 2.02 SS in, 1.64 SS ex.
Accel Dist, Coil, and wires.
Eddy AG RPM.
Eddy 600.
Comp XE268 cam, Comp Rockers, springs, lifters.
Hookers with flowmaster 40's dumped at the rear axle.
TF 904 with B&M Stage 2 (street/strip)

I am at my wits end trying to research the issue.
I can do the Pinion/ring swap etc, just need to know what to get and I cannot seem to get a solid answer from anyone.
Just lots of 'Um...' 'Well...'

Thanks very much to all who can/will help me out.
Bought the car last weekend and want to make it to the track.
:banghead: