70 duster street strip build

Tri y headers vs tti headers . So I ordered 3inch exhaust for my duster I get the header flanges for my tri-y headers out to find they only have 2 1/2 inch collectors . So I'm standing there thanking wtf . Now I'm understanding why its better to research everything to the fullest before pulling the trigger on any thing that cost more than 200.00 so now I'm thanking about buying the tti 2 inch tube 3 1/2 inch collector . What do you all thank ?