Why are 318's low HP and torque?

toolmanmike said
Ma Mopar basically used 273 heads when the teen was born. Now if they would have used 340/360 sized ports and valves and 10.5/1 compression Like the HP 273's and a solid lifter cam spec'd like the D Dart motor there would have been a
350+ HP motor from the factory. Just for fun, in the next few hours, I will put that combo in the ol' Desktop Dyno and see what comes out. I'll report back later. tmm

I threw some figures at the computer and came out with 382 hp@ 6000 rpm and 379 tq@ 4500 not bad for bolt on parts and a far cry from the rated 230 hp for the 68' model. (the 77' 318 had only 145 hp.) I used a stock bore 318 with 10.5/1 compression, stock heads with 1.80/1.60 valves, a single plane intake and a 750 cfm carb, and small tube headers, and a 284/495/505 cam. tmm