01-09-2020, 09:15 PM
Hi Brettfcars
Assuming your rear axle is a late Ruby 5.125 to 1, and the tyres are 4.00 - 17 with 803 revs per mile, the engine turns 4115 revs per mile in direct top gear. At a mile per minute (60 mph) the engine would be doing 4115 RPM. Or put another way, the gearing in top will be 14.6 mph per 1000 RPM.
45mph top speed sounds rather low to me, that's only 3080 RPM. I doubt if changing the gearing by 5% by going to your other diff would alter it much. Maybe the engine still needs some tuning to help it develop more power at higher RPM.
The speedo is a long way out, I'll leave it to others to suggest a cure.
Assuming your rear axle is a late Ruby 5.125 to 1, and the tyres are 4.00 - 17 with 803 revs per mile, the engine turns 4115 revs per mile in direct top gear. At a mile per minute (60 mph) the engine would be doing 4115 RPM. Or put another way, the gearing in top will be 14.6 mph per 1000 RPM.
45mph top speed sounds rather low to me, that's only 3080 RPM. I doubt if changing the gearing by 5% by going to your other diff would alter it much. Maybe the engine still needs some tuning to help it develop more power at higher RPM.
The speedo is a long way out, I'll leave it to others to suggest a cure.