An improved electrical wiring connector block in which the terminal lugs are preassembled at the factory, the blocks having knoblike protrusions formed thereon shaped and located to serve as anvils for crimping the lug ends on electrical conductors inserted therein, one or more connector blocks then being inserted into an associated housing wherein matching lug contacts of the blocks are aligned for electrical contact with each other, with contact strips in the housing, or with terminal strips of a printed circuit board inserted in the housing.