[RACER X #99]

After reading everything the Butcher had to write about MSD dist. gears, I decided to try and find out why my dist. gears are wearing prematurly.
The numbers that MSD gives you on locating the new dist.gears seems to be wrong and I concur with the Butcher. The pink sheet says 4.005 max and 3.996 min on base of dist. flange to bottom of gear. I tried a brand new gear with those min . 3.996 numbers and when I bolted down the dist. (cam removed) I could not turn the dist shaft. I moved the gear to 3.970( the exact dimension of a Ford dist. I removed from another 351W) Now when bolted in the dist. shaft spins freely and after reinstalling the cam the teeth mesh is correctly centered.

This seems like a lot of trouble to go thru to just install a new dist. But I only had 200 Miles on my new engine when the dist. and cam gear were both wiped out. Steel gear on billet roller cam and crane steel gear on dist. The initial installation I went strictly by the dist. gear instruction (pink) sheet.

It seems to me whomever you buy parts from always puts the blame for something going wrong on the other guy. The amount of questions and problems regarding premature dist. gear wear leads me to beleive that some of the big name manufacturers are not doing their homework.

The only advise that I can give is do not assume that the printed instructions are 100 % correct. Do your own measuring and fitting and if you are not sure how to do it ask somebody who is.

The best place to find the correct specifications are from Engine manufacturers manuals.

Hope this helps somebody,
RD