'84 C10. Replaced 305 w/ 350 B4 I got it. There are several wires coming from the firewall that I cannot figure out where they are supposed to go. They may just be for the old power plant but I just want to make sure. 1st is a 4 wire, waterproof connector male plug, black,Lt.Green,Yellow (or tan)and purple (?). It seems that it should go on the distributor per the original wiring specs. but there is no connection there. There is also nothing close enough that I can find. Also from the same group, a seperate orange wire with a double spade plug, and a 'funny' rubber cnnector in the middle of the wire. Any Ideas? FYI, Engine runs fine. Thanks.