Tecnick wrote:Cheers Paul, Could that translate to better fuel economy I wonder.
I'm not sure tbh. I can't see it making any difference round town as you'll just tend to be in a lower gear to compensate. On a long higher speed run you might find you get a few more mpg if you have enough power to keep it in 5th but if you're forever going between 5th and 4th every time you get to any kind of a hill then I would guess any gains on the level will be lost there.
At the end of the day if it was going to be better all round with a 1.22:1 box then they would probably have fitted one in the factory so I would guess that unless you have had the engine tweaked for a few more bhp then you'll probably find it less than ideal.
ISTR that when DaveW first built the 100" and put the box from his Rangie into it that it had a 1.22:1 box and he changed it for a 1.41:1 because the auto box was forever changing down from 4th to 3rd when cruising. You would probably end up with the same problem in yours, especially as you will probably have less horsepower than Dave's 3.9V8i.
Paul