I have had a Mitchell syncro about 5000 miles so far.
Best thing I did to the car in last 54 years ... hands down ... "Numba One".
There are 3 types:
1. Standard ratios 1st and 2nd.
2. 15% higher 1st gear
3. 15% higher 1st gear plus 15% higher 2nd gear.
The third is the one that I chose. Love the higher ratios.
It is a joy to drive in traffic and leaving stop lights.
Recently added Mitchell Over Drive and changed from 3.54 to 3.78.
The 3.54 that I had installed the last 30 years was just too tall for mountain roads and the 6000 to 12,000 feet altitudes.
Mt Evans is 14260.
Even with the B engine and Police head it needs the extra revolutions to climb the "Hills".