hi all, so i have had come into my position a sj410 (i think?)

it has had a shell we say a hard/fun filled life, but now is finally at no go situation, hence why it was given to me.
engine is a old subaru 1600 carby

, out of a leone i think with the hi lo box as well then a 4 speed suzy box with the hi/low box behind so as can be imagined 1st gear in low/low is almost slower than a wet week! i think it has 410 diffs, the front has a blown cv and no drive shaft, rear diff some one tryed to lock and is now shatted

, so all up i have a shell! now here is where you all can help!
Where do i go from here?? the shell is ok full roll cage raditor on the back, no windows or doors, just looks fun, but every thing i will do is on the cheep, is there better diffs do 413 or escudo just fit,? will ratios matter with 16 or so gears? motor wont die should i keep or biff it out? i just want it to be able to go for a bush bash for a weekend and it hold together and get me home. sorry for the long windedness but thought someone here might be interested and have some good tips?/ thanks all