A-833 2.47 1st gear change to 3.09

the 64 to 66 six cylinder trans has the 3.09 gear set. , it drops in, don't need to change reverse gear either, i had a friend , changed to a 3.09, from a 2.47 gear set, in 1/4 mile it was two tenths quicker, the 340 will pull the split on 1 -2 shift easy. i ran the same in my 340 car, go for it,just food for thought