If i were you,i would do what i did
Get yourself a remote change gear box (12G1128's are the best ones to use)and pull it apart,
then you go theu and replace what ever looks to rude to put back into it,while its apart you should ALWAYS fit a central oil pick up if it already hasnt got one(about $130),give eavrything a HUGE clean.the cleaner it is,the better its gunna be,then get yourself a 3:44 diff,these give the best in bottom and top end speed,they can be found in most rod change gearboxes and cooper S boxes.i put new syncro's in first and 4th,and NOS syncro's in 2nd and 3rd,as apparently the old ones were made better,and 2nd and 3rd get most of the power changes

.conver to CV joints as uni joints always brake when ya just getting excited (having a bit of fun),make sure you clean all your surfaces and have them flat,to stop oil leaks for years and years to come

,replace all your bearings and rebuild the diff and she should be good to go.
Watch out for them drive shaft's thou.one snapped on my bosses 110+ BHP Cross flow race car and it flipped 180* in the air,came down on the nose then slammed down on its wheels.he broke both hands,and fractured his back in 2 spots.
my complete gearbox/diff rebuild cost me under $500 with all new bits..but then again i work for a mini place
have fun with it and PM me for more info or help..