Agreed,
If you don't measure you don't know. I am at least 3 weeks away, from the dyno thing.
I can't tell how deep that cat area is in the crossover; and, if you can drill all of it out from the upper header entrance for the right muffler. Would it be a concern if some of that cat is left in the lower portion of the header obstructing that outflow to the left muffler? There's a welded ninety there, where it crosses over to the left side.
I probably to remove the whole header, take it to work, cut the 90 off and drill both sides upper and lower, get it all out. That will light up those new cores you can bet on that.
I spoke with TR at TMAN and he reccommends an entire 110 Kit: TB, Pistons, Cams, Head Work (porting, guides, springs, etc).
I asked Short Block Charlie for his reccommendations for a cam and head work without doing the pistons and TB.
He says he will get some info together for tomorrow.