Wize,
thanks for your thoughts.
Problem with going 3 1/2 inch on collector is i have a 3" system,my class is mandated an exhaust with mufflers with noise limits.
i guess i could go to 3 1/2 for the system,it ends in front of the diff
welding i can do no worries in my shop
Bullets lobe sep is 108
intake centreline is 104
Tex