Most burned pistons seem to be on number 7 & 8, why?

Would addiing pyrometers on header exhaust tubes for 7 & 8 help in determining overlylean?

Also, how do I expand the 4" solid intake pipe on my D1 ? I am trying to install used kit on 94Z.?

 

Most burned pistons seem to be on number 7 & 8, why?

Simple. The back cylinders run leaner because of unequal air distribution. They get more air than the front cylinders. The "solution", if you can call it that, is to have your set of injectors flow tested, then reinstalled with the ones that flow the most on the rearmost cylinders. This is one of those "secrets" most don't know about.... until now....


Would addiing pyrometers on header exhaust tubes for 7 & 8 help in determining overlylean?

Actually, yes. I have my EGT on #7 and tune to it.


Also, how do I expand the 4" solid intake pipe on my D1 ? I am trying to install used kit on 94Z.?

Can't help here. I own a third gen.

 

my only burned piston was #1...

 

I'm not sure what a proper temp is for a header tube on a properly tuned motor? I'm sure the temp goes up when the boost is on. There must be some safe max temp to watch for?

If they were not so expensive, I quess install one on each tube would be a good idea.

Maybe 7&8 lean out due to the air being pushed / blown to the rear of the manifold and thus filling those cylinders first?