I am very pleased with the swap to a ten tooth pinion. Our car is as follows. '27 Fordor, Stipe 280 cam, Prus iron head, Scat crank, stock iron pistons. Restoration completed last fall. Car driven around 500 miles before an original rear axle shaft failed. Replaced both shafts last week, and changed from 11 to 10 tooth pinion at that time. We live in a hilly area, and the car is much more useable. Doesn't lug the engine, and tops out at 44 mph, verified by GPS. Compression braking and service brake much more effective.

Vaporizer carburetor, Ford roller timer, stock coils also.

I'm not surprised you like it. My '19 Runabout had the ten tooth and it was too much. I switched it to an eleven and now it's just right. On a heavy '27 Fordor, I can picture the ten tooth being perfect.

I am going to install a ten tooth on my roadster pickup not because an eleven tooth would not work well for fifty percent of driving but because the weak stock crank does not do well with torque and most of the time with a well balanced engine and drive train say fifty mph with faster pickup getting into traffic is safer for the area I live that changes from flat to very steep hills every few miles.

I have had 13, 11, and10 tooth pinyons in my 15 Touring. The 13 made it a fast car that everyone else complained about when trying to keep up on the flat. Cruised easily at 40-45, but was a dog when going up hills, always in low Ruckstel. Before that, I had a Ford rear end with 11 tooth. Cruised just fine, but the hills still slowed me down and no Ruckstel was a problem. When taking the 3:1 out, no one had the 11 tooth in stock, so I settled for the 10 tooth for the Ruckstel. At this point, I am happy with it. Makes it a real mountain climber. Those that feel they have to go fast can just go on as far as I am concerned. When we come to a hill, and we have plenty in the northwest, I leave them behind. Almost don't need the Ruckstel now. I hope this helps. You will need to decide based on your car and how you plan to drive it. No one else can make that decision for you.

I totally agree with Paul!!