just for giggles....OMM can use my rule book and post the text....100% allowed and legal.
if the seats are 5 lbs lighter than "factory" seats....I would be surprised. The weight savings are in the (legal) aluminum seat brackets.
I have read the rule book from front to back and so far....as built, I have only found ONE thing that coulda /woulda possibly been deemed illegal.....and that depends on the meaning of what "is" is. Would not be considered a performance enhancer by any stretch. ......Butch Leal and the 396 cu in Hemi right out of his 73 Pro Stocker (both legal)....how much more trick do ya need?