Ignition switches and key cylinders

Even though many of the '68 and earlier aftermarket switches claim they fit all models, I know of differences in some applications. As you can see in the photo, one switch doesn't have the extra nubs sticking out for the later wiring plug that the other switch has. Not a biggie, but, if you're looking to be correct, it might matter. They also made 5 and 6 terminal versions, with the 6th terminal being a ground needed for some dashes. The most important issue can be the way the switch locks into the dash. There's a few different ways they do that so the switch doesn't spin in the dash when you turn the key. Some have a nub sticking out to index into a slot in the dash or cluster, others have a cut-out or flat that does the same thing, and they're not all in the same place. It's best to compare features when getting a new switch if you don't want annoying differences.