I never but helped my friend Auggie way back when 1_2 Years after high school. He had a 340 he messed up in a 73 Duster. (Had Auggies Toy airbrushed on trunk and his and girls names on doors, air shocks and 5 spoke wheels.
Junk yard low compression 318, J Heads to drop compression (rolls eyes here)
Aluimiunm Intake, 750 Holley duel feed, chrome valve covers, headers and loud muffs pipes dumped before rear end. Close to 340ish cam stock 904 and converter. No gears.
Car looked and sounded great. As his close friends we called it Auggies Doggie bet it was 8 to 1 compression or so. Did cruise nice on highway, sound good and got him and girl looks at the local hang out spots.