What year truck? Looks like a '78, unless that regulator has been relocated.
Edit: I don't know what your new regulator has, but the stock regulator looks to only need WG, BY, and WB. You may need to identify what wires you have at the regulator and where they connect in the regulator. You could open it up and identify the leads, or perhaps the information can be found online if you can identify the part number of the new regulator.
I'll give you the colors from a 6 wire VR (not specific your truck)
White/Yellow -► F
Black/Yellow -► IGN
Yellow/White -► L
White/Blue -► B
White/Blue -► N
White/Black -► E
The pin location in your oval connector is the same as the round connector is the same as the rectangular connector.
As there are 2 White/Blue wires you have to figure out which one is which.
Check with an ohm meter which White/Blue wire comes from the alternator N terminal and which White/Blue wire comes from the B terminal.
DON"T mix those 2 wires.
Some late 78 US spec models had the 6 wire voltage regulator. I would suspect that they are wired on the charging circuit somewhat like a '79 model but I can't say for sure. 79 models had cats, etc. I have a Canadian spec 12/78 wiring harness with a six wire VR
Just let everybody know when I was working on it blew a fuse that why it would not stay running . Replace fuse and now it stays running. One more quick question so when I put my volt meter on the battery when idle it reads 12.05 than when I rev it and hold it steady at a high Rpm it start climbing on the volt that means everything is working correctly am I right