Help find the missing link

[memo43]

Ok here goes
my truck is an 85 k20 with all stock gauges (no dummy lights)
I recently did an engine swap original 350 for a l31 350 (roller motor)
while I was at it I installed a summit max efi system.
New battery, new alternator.
The engine has the serpentine belt system. With that being said it had a CS130D alternator, which I thought was bad, changed it for a CS144 (140 amps) to supply all the upgraded electronics.

Now my issue with the truck off the battery reads 12.8 volts, with it running It reads 14.3
same reading at the alternator.
I have a relay bank by the headlights that powers the headlight, hi/low
dual ford Windsor fans. I get 14.2 v there as well. same for the bus bar that is tied to the battery (10 gauge)
My Voltage gauge in the cab reads 13.2. tested a few circuits at the fuse panel
some get 14.2 the majority read 13.2.
Only wires I change are the factory wires that go to the battery terminal, upgraded with 10 gauge wires. ground is ties to block and frame.
Main battery cables I upgraded to 4 gauge both positive & negative.
Alternator battery stud goes straight to the battery positive with 4 gauge wire as well.
I'm using the correct adapter for the alternator with the resistor in the L terminal, "S" terminal or sensing is 10 gauge to the right side of the junction block (as you are looking at it)

while driving I avg 13.4-6 volts. while driving at night if the fans kick on the headlights will dim.

Is there a wire that I'm missing (missing link)
(1)power wires from fuse block to starter is 10 gauge.
(2) starter to junction block is 10 gauge.
(3) alternator to battery is 4 gauge
(4) battery terminals are 4 gauge


what is the missing link or better yet how do I get the 14.2 volts to the fuse box to distribute to the entire electrical system.

thanks in advance