Custom duals to y pipe

My 70 Challenger is powered by a 225 Slant6. I am running a Super Six cast iron intake with a BBD Carter off of a 318. For exhaust I went with Hooker 3 into 1 headers. From each collector back I run 2.25”aluminized pipe in a true dual exhaust fashion with “H” pipe to connect both pipes. Then to a pair of 26” Walker glass packs then continue to back around each side of tank still 2.25” pipe with Cuda style bright tips under rear valance. I’ve had no problems with this set-up for years now. Can still eck out 18-23 MPG’s on 87 at the pump.