A 3.1 with 10 inch wheels in Florida will do fine.

LOL...not many hills in Florida. My wheels are original 10" steel wheels and oddly enough the car feels under geared to me. The engine is an MG1100 motor with +20 pistons. I guess I should be getting close to the 55 HP claimed for it as compressions are good and head (12G206) is in excellent order. I have no idea what gear ratios are in there. Is there a way to find out?
Steve

That's probably the best all around ratio for a street car with a reasonably powerful engine.  It gives you acceptable freeway RPMs and as long as you don't have a close ratio gearbox, and have good skills to manage your clutch, it shouldn't be too bad getting off the line.  If you do have a 1098 engine, my opinion is that a 3.1 is a little too tall, but others on here use them or even higher FDs with 998s. although I bet they don't have a lot of mountains to deal with!  A 3.44 or 3.65 would be better, specially if your wheels are 12" or bigger.... again, in my opinion...

The results are in.....the FD is 3.1  I had to split the engine and transmission anyway to check the mains and big ends. I also plan to pull the pistons to check ring clearances.
Any comments on the 3.1 FD?
Steve

You can tell quite easily your final drive ratio without it being the reason to separate engine and trans.... have a look at this short video from my youtube channel:

https://youtu.be/Ii5q4dmoQfg

Your 1098cc engine could pull a 3.44, 3.1 or 2.95 gear each one is slower off the mark than a 3.76. It really depends on where you drive and the terrain you drive in. I used a 1275 Mini with a 2.76 FD which was fine in Florida but up in Tennessee it was a pita with having to constantly shift up and down the box with the hills. What you have is way more acceptable than the 4.3 (i think) ratio the MG originally had.

I found a couple of great sources for transmission information and based on my research, it looks like my MG1100 motor is attached to a 1970 MK111 850/1000 transmission - If this is correct and if it has the original final drive, the ratio is 3.76, which would also account for great acceleration and much noise at cruise.

The car is unlikely to be doing any long distance drives so I am not concerned about the noise.

Anybody have experience of this FD ratio and any opinions on if I should change it?
Today is gearbox separation day so I can check these findings,
Steve