I would fix that vacuum leak before you change any thing else. with the bypass I think you have to change the timing which you wont be able to do until it will idle good for you. The Bypass should have been done when the weber was installed. Also look into changing your rotor and cap to one from a 82 ford F-150 with the 300 motor in it. You will need cap, rotor and adapter. THe cap is bigger and they say it will prevent cross firing of the sparks by the rotor. .
88 YJ 35's 8.8 rear, family style roll bar, ax-15 external slave conversion, Custom double D fab dash 4" of lift taurus fan, Head light wiring upgrade, MSD 6al, JB conversions SYE, 258 with RV cam, Long tube headers, Borla exhaust. 1"mm, Auto meter gauges.