Wake up a bit and 1 hp/cubic inch really don't belong in the same sentence. You need more compression to start with. Probably a bigger carb too. I would keep a solid lifter cam too. You could start with the recipe that the 66 D Darts used. They were rated at 275 horse. They had 10.5/1 compression., (Probably more if the truth be known) , headers, 700 cfm Holley, open plenum intake, a .495/.505 284 degree solid lifter cam with 300# open pressure Springs. They used a 4 speed and 486 rear gear. The build was not a streeter by any means. With your low compression 2 barrel, it is so easy to over cam it. It would be best to just stick with some tried and true bolt ons.