Wheel diameter

[Erich]

This brings up a question I have. My Ulster Rep has 19 inch wheels with 3.50 tyres and a 4.9 rear end. I also have a set of 17's with 3.50 tyres. I had thought that would lower my ratio. Is this going to make a difference, or am I mistaken? Next year, I am planning on competing in the only hill climb in the area(and one of the few in the US) that is open to prewar cars and so does not require fuel cells, roll bars, etc. It is run on the oldest paved road in Washington State. The course is 3.6 miles long, 8 hair pins and nearly 600 feet of gain for a 5% average grade. Any thoughts on whether changing to the 17s will help or should I think about a rear axle change to 5.25? Here is a video shot in a TR6 for an idea of the course. I should mention the car runs very well, has a torquey cam, larger valves and a Ruby head, all built by Pigsty. I do not know what the power is. https://www.youtube.com/watch?v=RWKaJ2fZOrg