Injectors?

I have a 71 855 small cam 350 I’m going to run my overhead and I’m not sure what injectors I have pt or top stop. What’s the best method for this and how can I tell without pulling injectors. I thought I would have pt but was told someone could have used top stop in the past

 

Is the method the same for both types is the outer base method required I noticed a lot of people do the inner base method

 

Another question I have is ,my tach is unhooked is it as simple as finding the correct wire and running from fuel pump to tachometer. Guess I better start looking for one of those wires to purchase

 

Thanks I’ll check my gauge connection and see if it’s the same and also look on the bell housing

 

This is the back of the gauge I don’t see any thread on connection, maybe someone changed it over and that could be why the cable is missing from the pump. It looks like the original gauge for a KW looks old like the rest of them