Ingo,
Yachtcare posted this link a while ago. Go to the the bottom of that page and there is an RPM calculator(at the bottom of that page is "For Specific Transmission Ratio"):
Plu in values for the variables:
- 4.11 (stock '51 1/2 ton) vs 3.55 (Patrick's) rear end ratio (R & P ratio)
- 28" to 31" Tire Height (loaded diameter)
- 50 to 65 MPH
- 1.00 Trans Ratio
http://www.ring-pinion.com/calculators/calculatorsind.html 2,500-2,700 RPM seems a reasonable range (cruising at 3,000 or higher for long periods might be a strain).
Several people who frequent this forum have installed Patrick's conversion. Maybe they will give testimonials.
Tim
