Original or Survivor Class Rules??

[Muellers69GMC]

I am new to rebuilding and restoring these trucks and am just wanting to hear from those in the know about what kinds of things I can and can't do on the truck if I am going to show in these classes.

My truck is/was basically a survivor (bought new by my grandfather)...at least until I decided the engine needed a rebuild. Now I am trying to keep things original, but somethings just aren't that easy. For example, both exhaust manifolds broke in some form or another. One was cracked in half and one had broken stud holes. Also what about things that improve drivability, say for example adding an ignition module.

Just looking to see if there are hard and fast rules or what peoples experience is.

Thanks!