If you can go to a solid cam, I'd make the switch. Something in the 240's at .050 and .520-.550ish lift. Even if you don't switch, run a hyd cam in that range and you'll have enough to hit your target
Intake, run what you have. The LD340 is a good intake and it's not worth getting rid of it for an RPM or Air Gap intake. Use the LD and a 1" open/tapered spacer, it's more than capable and will move more than enough air. Top it with a Holley 750DP.
ET is about chassis and converter efficiency. Get the car to 60 foot an the rest will fall into place. Poor 60's mean you need to make up that lost time through excess MPH for your ET. 7.50 1/8 is around an 11.80-90 1/4 mile time.
Put the best converter you can afford in it! It's the single most overlooked item and unfortunately, IMO, the most important piece of the puzzle.
