When I got mine ( a 69 400 vert.) that stiffener plate was missing....Also mine has two straight pipes w Glasspaks, then to 71 model T/A tips, but there was no problem installing the stiffener plate...it cleared even my 'aftermkt'pipes...But you `ll want it there to stiffen the body , eliminate twisting...I got mine new repro from Ames ,not sure what i paid ( 2 yrs ago),but I think around $85.00, this plate is often missing because its removed for tranny work...and often not replaced...its the same piece for 67-69... You can sometimes find these on EBay , but usually at the same cost as new...Mine did not come w bolts ,but those 6 bolts you can just match one to the hole and buy them at hardware store..no bushings,its supposed to be rigid. its called " convertible under body stiffener plate " or such.... Bjorn
