Ok so these are the items I have received so far..
2.25" universal magnaflow cat
bolts w/ springs kit
bosal 2" donut gasket (dont think its gonna fit obviously)










So i ordered a 2.25" donut gasket from ebay

and 2.25" flanges to weld on to the car, 2 bolt flange between header and cat, 3 bolt flange between cat and rest of piping.

though now im thinking... if the inside of the donut gasket is 2.25" the outside must be a little larger and has to fit inside of the flange on the cat-side... so i have to get a bigger flange...? or am i just being silly

and these springs with bolts not sure how they're going to fit through these flanges and on which side of the flange....

also this cat looks kinda big, bigger then my 2.5 high flow cat. maybe cuz of the extra protection shielding. not sure if it'll fit snug under my car...