Headers in my early A body...HELP

I have Heddman Hustler fenderwell headers(1 7/8) on my 66 Dart.I had to cut the inner fenders for them,but they are easy install/removal.After I did this(5 yrs ago) TTI started making 1 3/4 under chassis headers:violent1:.I would go with the biggest primary tubes you can get,for that stroker to work.Mine is a Eddy head 410 c.i stroker running mid 10,s.