Lost all power and lights are super dim

[NoForAnAnswer]

I just found this forum last night and I must say I like what I see.

I have a problem with my 1971 K10 4WD 350 TH350. I can't get it to start. I turn the key and nothing happens, I can turn on the dome light and it's very dim when I start to crank it over the light goes out. I just got done replacing the starter and checked the battery. Battery's got power, alternators got power, solenoids got power, ignitions got power. Battery cables are in decent shape and were working prior to the truck not starting. The ground is good. I took the bolt off the block and cleaned and wire brushed it so it would make a good connection.

I tried jumping it and all that did was allow me to turn the headlights on and I got it to crank over but really slow like you've got a dead battery.

Any Ideas?

My dad bought this truck in 1983 and it's been mine for about 11 years and I've been working on it ever since I was little so I know quite a bit about how it works but somethings I just can't figure out.

I thank you all for the help.