Hey everyone, new to this forum. I have a '74 620 with an L18 that the previous owner did some 'awesome' wiring to. I was wondering if someone can post/send me some pics of the headlight relay. there were two metal relays on the front of the truck on either side of the fan shroud that the PO said were the headlight relays and that they were faulty. I got a new relay from Rock Auto and it looks NOTHING like either one. any info would be appreciated, thanks everyone!

Normally, I would not do this, but we do not have the manual you are looking for. Here is a forum that has the diagrams you'll need.

http://www.davidcmurphy.com/olddat/620tech.htm