Cannot shift into any gear?

I thought it was pretty dirty or so it seemed. I'm not sure what you mean by trouble filling it. I can't say that I did. Just put two quarts and about another third to a half, re-plugged it and then drove it around some.

The fill plug was on the side of course and the transmission itself was up close to the undercarriage which made it impossible to tip a bottle into it, so I just ran a clear line through the engine bay and down to the fill port and poured from above the engine bay. Anyway, it makes me wonder if my original clutch installer from the very beginning, (Dave) was right in saying he thought it was a bent clutch fork. Is there a way to diagnose if it's the clutch fork specifically? That would prevent the pressure plate from releasing completely, right? Or if it's a bearing or something misaligned in the clutch itself it presents a somewhat major effort to fix. On this truck the exhaust system is one piece from the headers to the tailpipe. They had to physically cut the exhaust pipe, (no place at all to disconnect it to access removing the clutch), then everything involved in unbolting the tranny - driveshaft, unbolt tranny, pull axles out, etc. I'm not afraid to attempt that. I'm really good at R and R, it's just that I don't have a garage. Anyway if I drive it the way it is and avoid first gear for the most part, (I can drive in reverse as long as I turn engine off first, then put it into reverse before starting again) can I drive it that way until I can find time to look inside the clutch? Would I be wearing out the pressure plate and or the bearing or something? It drives totally fine (except first gear) while the car is moving. No grinding, no problems at all. You really wouldn't know there's a problem while it's moving. Only after I come to a complete stop. Bu then I can put in second gear and start moving again just fine. Sorry, this is so long. Thoughts? Thanks, Jose

Hi again Joe,

I have been driving the truck since last we talked. A little tough shifting at times but drivable. Yesterday I checked clutch pedal travel. Found my nut to Master Cylinder was not tight. Adjusted MC rod clockwise about 1/4 in, tightened the nut and freakin shifting is way better! Not perfect but dang near. So, So awesome. Thank you so much!
New question though if I may.
Heater became noisy, air flow was limited and cool.
Removed blower past Monday. Found it full of leaves. Cleaned it out and reinstalled and instantly had strong Hot air blowing. Temp gauge was at normal operating temp at this time and normal the entire time I've been driving/ Never showed signs of overheating at all.
The next day (Tuesday) I still had strong air flow, blower was working and quiet, but only blowing Cool air now.
Coolant level is good, up to neck filler tube and proper mix.
All heat controls seem to be working. I'm assuming the door(?) Is opening when I switch from cool to hot, because on Monday I had heat! Hot and strong and everything working. Next day it's no longer hot and I did not do anything. Nothing at all except a visual check of coolant level, Didn't need to add any.
Temp gauge still operates normally. No overheating signs at all.
Top radiator hose gets hot, bottom hose stays cool or slightly warm.
Heater core hoses has lower one hot and upper one warm.
Assuming water pump is fine. No signs of leaking and not overheating.
So would you think my Thermostat is stuck open or closed? Maybe clogged radiator?
It did sit for 2 years but I've been driving fine since July and again no overheating symptoms. Or does it point to my heater core?
Heater core requires dash removal I think, yikes.
If it's heater core, I could use a backflush/unclog procedure process from you and hope for the best. Or if thermostat a R and R procedure for that would be appreciated.
Or radiator clogged possibility?
Lastly, some advice from you on tests to do to isolate and confirm my issue.
Thanks again so much, Jose

I totally understand and it's not a problem. I already submitted my heater question on a new thread. You have been extremely helpful and it's very appreciated.