I loved my ‘68 Chevelle SS 396. You’re of course right about the ‘68 Firebird 400. Like the ‘68 Chevelle SS 454, it was easy to make that front end lift off the ground ... even with its heavy engine block! But smooth sailing on straight roads (like the Ohio Turnpike at 3 a.m.) at 90 or 100 (not that I ever did that ... heh-heh!)
We had bias ply tires and drum brakes....but it was a blast!