I need to sell a few things ASAP so I feel I priced these accordingly.
I have a pair of stainless (not sure which grade) LS1 header flanges. They are 3/8ths thick and should fit 1-7/8" or 1-3/4" pipe alright.
I also have a set of 1/2" thick mild steel C6 vette manifold flanges, usually used for turbo setups. I run these on my turbo car. They fit 2.5" pipe.
$50 shipped MeanYellowZ@hotmail.com