305's have 19lb/hr injectors, 350's have 22lb/hr injectors, a simple bandaid, get an adjustable fuel pressure regulator and bump the pressure till you get it runnin the way you want it to.
www.TPIS.com there a shop about 45mins from my house and the specialize in this stuff. ge there phone number from there website and talk to Jim Hall, he can probably answer all your questions.