Gear ratios & highway speed

[Ken Hughes]

Hi Phil, The F30 originaly had 10x50x16s fitted and the speed was the early 30s,bearing in mind the v8 is not fully run in.
I have now fitted 8x25x20s on military rims made by GM !! as the 16s were all cracking in the tire walls and treadand cant source local tires of 10x50x16.
The original 20s were 10x50x20,and the speedo drives were different in the number of teeth fitted(in parts manual).
With the 20s fitted it looks like the truck has grown up!.
The difference between an F30 and a F60S is the 60 has an extra leaf spring in the front springs, bigger stearing ends,although not allways.and air assisted breaking system and wheel size, oh and somtimes a bigger stearing box.