B&M Converter is bad

Sounds like you have it idling good, 15 initial should be ok for that cam. at any rate the weak take off may be the sqirter/pump shot now. With the engine idling and in park take the throttle by hand and just barely move it off idle you should see gas squirting out of the squirters at the same moment you move the throttle (not a 1/4 sec after you move it) RIGHT AS YOU MOVE IT.