The V8 Owners Forum -

I have a 4 speed with overdrive at the moment but im in the process of restoring and making my stag more fuel efficiant.

the LT77 is an OD box, meaning the 4th is a 1.1 ratio and 5th is 0.7ish giving an overdriven 5th

in the US companies like "gearvendors" do over drive and overdrive/ underdrive boxes as adons/replacments for the tail section of some manual and auto boxes. it very much depends what you have and what you want, I do not imagine it would be a cheep solution even if you found a compination as you would have to adapt a us box to a primerily UK engine ( I am guessing this is for a rover) however I think there is a combo of T5 (but the mustang version not the sierra) and a tail section replacment gearvendors overdrive unit http://www.gearvendors.com/aghr4sm.html
Yup try that!!
However as I said it won't be cheep you are going to have to drive a long way on a motorway to get your money back!
Best regards
Mike

I have fitted a unit an external units from this company >>>> http://www.odspares.com/

It was for a friends car and has yet to be driven as its still in the body shop

It did work out quite expensive to do - over £1000

Thanks guys.

I see a lot of questions regarding the LT77 so this is going to probably sound stupid but do people rate them then?

As i say im going to start the restomod of the Stag this winter mainly because i know its going to fail it's MOT so i'll probably be asking a lot of questions.

LT77 is marginal with a standard rover 3.5 and a range rover, 3.9 and a range rover it will probably last about 75 to 85k before it is knackered enough to need replacing tow a boat alot and it will even qiucker . Stick it in a lighter car and it will last longer (3.9 in a seven replica and it will last 130 k of so)
R380 was reconed to be quite a bit stronger but is primerily a RR box (though I think some ended up in 2wd form in some DAF vans).
Mike

Some oldish Volvo's run an overdrive unit.