Jon.. or others.. My car.. 66 Fairlane, I am finishing tube chassis strut front end because I want more out of the motor and i believe the bottle neck is the Maddog 2" primary headers.. So I'm going to move motor back 6" and make my own.. Question is should i start with 2 1/8" or bigger? and where do i make the steps up to 2 1/4 and do i go as big as 2 3/8"? No port work.. out of the box p-51's, motor builder touched up ports to match is all.. Comp Cam.. 272/284 773 lift.. on a 111.. we were trying to make up for 2" primary tubes that turned immediately after the flange.. Also.. 1170 wet flowed ProSystems Carb on 110 race fuel.. So what is your experience with step headers and how long should tubes be before collector? Thanks!!