Top mount / side mount? Distributor question

Everywhere i go looking for an engine asks me if i have a top mount or side mount distributor, Whats the difference? and what would it hurt if i got a side mount dizzy  motor, and put my old top mount dizzy on it?

This is a 95 blazer 4x4 w/ a top mount distributor

 I have never heard of a side mount distributor in a blazer with a 4.3L engine?
What's a side mount dizzy motor?
I've been turning wrenches for 30 years but I'm unfamiliar with this.  I can only think of some 4 cylinder engines that have the distributor mounted sideways, driven by an overhead cam, (like a 92 sunbird 1.8L) that have that setup.

Referring to the position of the wire terminals on the cap.  Top mount has the wires vertical out of the top of the cap while the side mount has them horizontal, split per the cylinders on each side of the engine.

so can i just swap my old distributor on the new motor, or do i need to go find a new motor?

quote:

ORIGINAL: Chevy Lover

 I have never heard of a side mount distributor in a blazer with a 4.3L engine?
What's a side mount dizzy motor?
I've been turning wrenches for 30 years but I'm unfamiliar with this.  I can only think of some 4 cylinder engines that have the distributor mounted sideways, driven by an overhead cam, (like a 92 sunbird 1.8L) that have that setup.

Canadians... :P jk

You should be able to reuse your distributor on a replacement CPI motor if it came to you with a side mount distributor.  In fact, you will need to.