so pulled off my old gear to measure shaft size thinking I'll just re use the roll pin hole for the new one and never measured where the gear was before.

With the roller cam swap I needed to get the steel gear so I picked up a Msd gear.

Now the instructions give you a distance to measure to know when the gear is on the right spot but is doesn't specify if it's measures from the edge of the gear tooth like it looks in the pic or to the face of the end of the gear which is .035" different then the edge of the tooth...
So i measured to the edge of the tooth and added the .035 (couldn't get accurate reading with vernier to the edge of the shaft and the collar the tooth was more accurate) and right now it's at 3.965 + .035 = 4.000 From flange to outer face of gear which is between spec according to the paper but before I drill the new hole (instructions said to turn the gear 90* when installing and drill new hole for pin)

Am I where I need to be or...Does is measure to the tooth edge?

 

By looking at the drawing it looks like you measure to the gear teeth. What's the part number of the new gear?

 

Here's the new gear and instructions

 

Ok I think I have it figured out.
Measured the block where the shoulder of the distributor siys to the bottom as 4.020" so I need to have less then that for the gear not to hit with the shaft pulled out when measuring.

With the distributor gear driven all the way on up the the shoulder on the shaft. I get 3.982 to the edge of the tooth.

3.982+.035= 4.017* with the shaft pulled all the way out which will leave me with .003" clearance between the gear surface and the block.

 

**** but then I read this and it sounds like the surface of the gear is supposed to run against the block and be able to lift it .005" up off the surface.
So then fully compressed I should be 4.010-4.015?

 

For ****s and giggles install in the old roll pin position and measure.

However, this may be quicker to solve by calling MSD, and asking them directly.

888-258-3835

 

This is the best way to install. You just need to verify that you can lift both, don't sweat the .005 measurement. Meaning you can check from the top of the motor if you already have the timing cover on.

 

In the ford sheet it says to verify shaft end play is between .024-.035" I get roughly .050" on mine.

That being said I should be safe to split that.
4.020" bore
Set the gear at 4.040-4.045 should be half way through the play.

Or am I just over thinking this

 

Install the distributor. While holding the shaft down,the gear against the block, you need to still be able the pick up on the distributor body. Now hold the distributor body down and pull up on the shaft. You should be able to lift it a little. Raise/lower the gear on the shaft until you can do both. This is better than just using a measurement because you know it's correct. You can install without drilling/pinning until you get it right then remove and drill.

 

Well that makes it sound real easy lol thanks!