Speedway has a mild steel 2 1/2 inch kit, plus hardware and other pieces. I have dealt with them a lot in the past, good people & products.

Jegs also has a large variety of pipes from several companies. I put one of their their brand name flex couplers and band clamps under the cab (lack of flex in the pipe kept eating my collecter gasket), they are solid quality pieces.

1956 GMC 370 dump " 'Tater "
1970 VW Volksrod "the Black Bomber"
2007 Chevy Avalanche
2020 Jeep Cherokee Trailhawk,
2005 Harley Davidson FLHTCUI

I dig all cars, old and new, whether they were hammered out of American iron, German steel, or Japanese tin cans. Being unable to appreciate them all is missing out on a world of great things.
But thats just MY opinion! :P