The LT77 from a 4 cylinder engine won't fit straight on a V8.
There is a variant of the LT77 which was used in the Range Rover... it's normally referred to as a 'Longstick' Variant. This will go straight on the back of a V8.
On a 3.5 V8 you will probably be OK for a while. I have been running LT77 boxes in my 90 (4.0L GEMS V8 ) and it's just eaten the second box in 18 months.
The LT77 is not a particularly strong box.
The LT85 is stronger, but are hard to find and expensive. Again, this should be a reasonably simple fit.
The LT95 is the 4 speed box as used in 110 V8 and earlier Range Rovers. These are very tough... but not as pleasant to drive.
If you have a 4 cylinder LT77 box which is reasonable, your best bet would be to get a conversion kit to fit it on a V8. The boxes are reasonably easy to get on the second hand market if it fails, and will be cheaper to repair than any of the others.
If you could find one for decent money, the R380 is a much better box... but they are expensive and did tend to have trouble with poor bearing lubrication on the earlier units. (again, the diesel and V8 variants are not directly interchangeable)
I am in the process of putting an auto box in mine... I can't be doing with breaking gearboxes every 18 months... it's too expensive
Give QT services a call for a conversion kit to fit an LT77 to the V8... Dave will be able to sort you out with the right bits.
www.qtservices.co.ukHope this helps.
