I have a question for all the technical minded people. Stock 87 Sammy with a fresh rebuild on a 1.3L 8V. Swift flat top pistons, head and block decked to clean surfaces. Head rebuilt with 1.6 valves, ported and polished, Delta Cam 272 grind, degreed, and lash at .007/.009. Distributor has been re-curved to provide 22deg advance by 1800RPM. Timing is set at 14deg base with a total mechanical of 36deg. I am, however, still running the stock carb. Wide-band O2 runs 14.6+/- cruise and drops to 12.1+/- full throttle. I have about 1K miles on the engine now, and it still does not seem to be running right. Low power, sluggish, poor mileage(18-20), will barely hold 55MPH on flat ground in 4th (LT215/75R15). Hot compression is only 150 psi, throttle open. Leak down is 3-5% across all. I'm at a loss as to why the compression is so low, and think this could be the power issue. Anyone have ideas on what could be the problem?