I have a Halibrand quick change on my 1953 Chevy pickup. From the attached photo's can anyone tell me with some certainty what gear ratio I am using. The top gear is a 23 tooth gear, and the lower gear has 25 teeth.
I checked my 6 spline spur gear chart.. If you have a 3.78 R&P you have 4.11 on the high side & 3.48 on the low side. If you have a 4.11 R&P you have 4.47 on the high side & 3.78 on the low side. Ask Gearhead QC on here he's the resident expert.
It's simple mathematics ..... 25 / 23 = 1.087 x Ring & Pinion Ratio (Gears Reversed) OR 23 / 25 = 0.920 x Ring & Pinion Ratio ( Gears as is now)
Jack up one side only ..... rotate the elevated wheel exactly one turn and accurately count the number of turns the top gear makes. Half this number and that's the R&P ratio. You'll need help too ......