There should be a hole you can put a bolt and nut in to lock it out. Or just weld it.

 

Depending on what exact model you have, most MSD distributors come with directions to properly lock them.

 

If you just remove the weights and leave the springs in, the cap phasing probably won't be anywhere near optimal.

 

Isn’t it worth three minutes to do it correctly and have rock solid timing!!!

 

Put the bolt in it to align, then weld. Even with the nylock and blue Loctite I still had it loosen enough that the timing changed slightly.

 

Pull the spring and weights.
Remove the dist gear the shaft will slide out and index it 180 deg.
Then slip the bushing pin into the hole that msd made to lock it out.
Now put it back together

 

This is the correct answer.

 

MSD sells weight & spring/bush kits for if/when you change back and you can't find the stuff.

 

There are videos on YouTube showing how to do bbn it. Not that big of a job. Good Luck!

 

^^^^^^^

Here's a video. Sounds correct, but it's been a while.