not sure about the carb, can't help ya there... but the HEI would be the best bang for the buck, if you do it your own way and not with a whole new coversion from mopar. then you can open up your plug gap to around .040 or so, should make a "notcieable" difference with good plug wires, blaster coil, and a step up on the jets. you might try and advance your timing a few degrees too. my dart has the old points setup, and always felt a little "retarded" in time, so a few weeks ago i advanced the timing a bit, it really helped it, i could barely notice on top end, but low end, and mid range improved a lot. i'm not sure how many degrees i put in it, i done it by ear, no start up issues or pinging issues.... there is one long slot in the dist. clamp, with 3 bigger cuts for the bolt head to sit on. mine was locked down in the center, which is probably 0 or somthing, one slot is advance, one slot is retarded, i'm guessing each slot is probably 5 or 10 degrees, anyways i put it in the advanced slot, then reset the idle, nice gain for 5 mins work, with no issues.
