I think if you had firewall tearing you would have no clutch release, not a slipping clutch.

Those prices sound real good.
How much is a rear main seal?

 

rear main seal about 11 bucks one piece


do I have to drain the engine oil to do he rear main seal?

 

oh and it doesn't like to go into gears sometimes ( when it warms up)
it wont go into reverse ( I get it is a none sychro 1st and reverse but....) at a complete stop it should go into reverse and sometimes it grinds going into other gears shifting normally ( warmed up I have that problem )

 

You shouldn't have any spillage.
The oil level is not that high.

If you have -dis-engagement problems check the pedal shaft bushings and the connection to the master cylinder pushrod.
Does your truck have an adjustable master cylinder?

 

the clutch pedal assembly , bushings rods ect are good
the master cylinder is non adjustable ( I don't think it is any way from what I have heard)


plus I have scorched the clutch in it several times anyway (hills what not)


plus unknown actual clutch mileage


its been hard to shift at times any way ( I know manual clutches my dads 1967 240 toploader f100 was going bad it acted just like this does - new clutch problem solved)