340 stockers

On the F/SA Barracuda....he has 3 engines that they cycle thru....all are difference in some ways...camshaft.,,.ring packages...One of them is an R block.... rod and piston has to weight a specific weight....but most of the rod weight is in the big end.....intake ports are cut to match required volume then thicker intake gaskets are used to increase the volume....bunch of tricks..T &D rockers now...beehive springs...race pak computers....

His 904 has a 2.66 1st gear...the 71 Duster has a 2.89 1st gear I believe or even steeper...

they are professionally build racing engine using "stock" parts...LOL...expensive...especially if you want to be fast in your class...