That is definitely a Sprint. 4.1 Litre and can see OHC emblems on hood. If numbers match, that is one of the rarest Firebirds.. Only 200 convertible Sprints made (out of 1,200 total '68 Sprints), if I remember correctly. The Rochester Quadrajet 4BBL has been changed to a Holly and the intake is aftermarket, but if restored would EAT V8's in the quarter no problem (I know because I've driven one for the kill).