Also, what is the recommended ratio for highway driving?
Standard TD 5.125 3900rpm @ 55mph (What I have now) TD option 4.875 3700rpm @ 55mph TD option 4.555 3470rpm @ 55mph (Gears available from Moss) MGA 4.3 3300rpm @ 55mph MGA 4.1 3120rpm @ 55mph It depends upon the type of driving you do. If all you do is freeway driving across nice flat states, the 4.3 is good. If, like me, you do a bit more hills, I find the 4.55 ideal. Don’t consider anything lower ratio than 4.3. Since the TD transmission gearing is different than an MGA, don’t expect that you’ll get the same RPM/Speed combinations as the MGA. I find that with a 4.55 rear end, I do just about 60 MPH at 4000 RPM. I can also happily do 65 MPH, at about 4250 – 4300 RPM. All this with a slight reduction in hill climbing ability. I know find, with a 4.55 ratio, that hills I used to take in 4th gear, now require 3rd.
