Welcome, here's couple ideas
For reliability, if you aint got a H.E.I. distributor get one, I bought a Petronix but a good new old stock GM one would be best I think the '76 trucks already had that as an option
For performance, I am giong to go the Vortec cylinder heads route by copying the Chevrolet Perfomance 350 CID 330 HO Engine specifications for the top end part number 1921007, git some used Vortec heads off of a 1998 Chevy Truck part # 12558060 are the good ones, the other part numbers aint so good, Edelbrock RPM Air Gap intake manifold #7516, etc. built it yourself if you can
http://www.chevrolet.com/content/dam...e-19210007.pdf