Nathans F15A Resto

[Jacques Reed]

Originally Posted by Keith Webb

Great to see you're getting stuck into your project.

It's worth checking the diff ratios (stamped on the front of the diff housing) to see if they're the high ratio for 16" wheels or the lower ratio for 20" wheels.

Hi Nathan,

You may already know this but it may be of use to you and others. the attached photo from an earlier post shows the numbers Keith was referring to.

"639" is 6 teeth on pinion and 39 teeth or ring gear giving a drive ratio of 6.50:1 F15-A

"643" is 6 teeth on pinion and 43 teeth or ring gear giving a drive ratio of 7.16:1 All larger CMP's with two speed transfer cases and 20" wheels.

Hope this is of some help to all.

Cheers,