Starter grinds when trying to start

Is this before or after it starts? Or does it start the engine? If before it cranks/turns over motor it may be a bad spot on flywheel or starter gear or starter is not fully engaging the flywheel if its starter just need to replace it, if you used a re-manufactured starter then its likely bad, If its after it turns the motor over starter may not be disengaging, may can have someone hit it with a hammer while it does it if this is the case or replace again. May be misaligned or came loose, or broke a bolt holding it. If its the flywheel only choice is to replace it, you may can get by with using a crank wrench to turn the motor off the bad spot, and keep cranking it until you can replace/fix it.

I would have a look at it to be sure its the starter or flywheel and not a flywheel nuts loose or something else.

Flywheels can come apart.

I would pull the starter to look ate teeth on its gear and teeth on flywheel.

Missing or worn teeth at the starter ring gear.

I have taken the starter off and there are no missing teeth on it or the flywheel but there where metal shavings inside where the gears for the starter are

I think I would try another starter. May can test that too.

is there anyway a bad connection somewhere can cause it because the wiring in the truck is kinda sketchy and strung out???

Low voltage or loss of voltage can cause a starter to not fully engage the flywheel, Yes for sure. Its well worth it to know your battery & battery terminals & terminal wires are good, tight, not corroded, grounds to frame from neg - battery to frame is good and ground from engine to frame. One way to check for this unless the connections or wires are very bad is to use a jump box or another car running with jumper cables to yours to see if it cranks fine. May just be that, also the longer one sits the more issues come to light with battery & terminals, without use the corrosions is left to grow and render them useless.

As a side note to your issues, you may should also be looking into parasitic battery drain and that is whole subject all on its own and also a sitting battery corrodes on the inside fast, if it shorts across all plates this will send out the rest of the battery charge into your electrical system. This can if battery has enough juice fry your battery terminals and continue until all lost juice is displaced into the frame and then onto other wires ground first or any wiring connected to battery & alternator. In other words you may have bad wires from this. If wires feel stiff or crackly then they could be fried and can fry apart too, may not be noticeable threw insulation. I would look for any bad wires or grounds and fuses too. Check for parasitic drain. Test battery under load at your local parts store. I would test the starter too while you have it out. The metal shavings is what has me thinking there is another issue there since you see it now, I would be certain the flywheel is not damaged, the flywheel has a tooth ring, that may have gotten out of alignment. Starter if working fine before should be in alignment but alot of the older cars/trucks needed shims so I would also investigate shimming it.

I have seen a many of the older trucks & cars with wire harnesses that have been pulled out and never put back up together and hang out of the dash and even down to the ground under it, So look for bad places and test and if you can try to put it up together afterwards, It very well is worth it to buy a wiring harness for it, Locate and note all options and engine and buy the one that is for your model and year. There will be a few things to adjust and add like connectors. I would also buy a new fuse block to connect too. Wiring harnesses are not as hard to do as it seems and makes figuring out un-located issues easier. You can get just engine and/or dash too and so forth to include the lights front and rear. Also, You may have the old style fuse links, check them too. A multi-meter may be your best friend, even a cheapo from HF.