lt77 vs r380

[angryman]

need some advice I have got a 1988 rrc that has a 350 Chevy engine in it (drawn out project) what box is stronger a lt77 our a r380 I have both sitting on my garage floor at the moment and would like to no what way to go all so got a lt95 but don't want the head aches of cutting out the floor pans what to do?

also got 2 transfer cases the old style gear one and the viscus coupling style any ideas

[pop058]

The LT77 upto 84 and post 84 are different. The most obvious is the lenth and position of the levers. The early box has a long stick and the diff lock lever toward the rear with the later box having a short stick and the diff lock lever in front of it. The 88 was the last RRC with the manual difflock as the viscous centre diff was fitted into the 89. I have been advised to leave a second hand (with unknown history) viscous diff well alone.

If you have the early LT77 and choose to use it, you will have to modify the floor pan in your 88 anyway. For all the effort, go with the R380 although the LT95 is the stronger of all 3.

[manic]

R380 suffix L is the stongest of the R380's AFAIK.

[Lotz-A-Landies]

And R380 is always stronger than the LT77, mostly in the 30mm extra on 5th gearset.

If you do fit an R380, make sure you also fit the external oil cooler. This both cools the oil and increases its circulating volume adding extra cooling effect.

[Red90]

Boith will explode behind a Chev 350. Put in a gearbox designed for the Chev and adapt to the transfer case.

[V8Mitch]

Lt85 or lt95 would be the way to go... Or a box built for the chev... Tremec t5?