heater core & dash lights 1990 Toyota Pick-up

[autoxr]

I just purchased a 1990 King Cab 4 X 4 with a V6 and 5speed. It has the original clutch and over 330,000 miles! The main issues I have are:

1) The heater core sounds like a water fall. It puts out heat and all but just makes a racket of rushing water. Is there a way to bleed the trapped air, which I am assuming is the problem?

2) The dash instrument lights do not work. The other dash lights work. Any thoughts?

3) The fan switch works for "off and high", the detents between seem to be worn out. Is the switch replacable?

4) Anyone know the hp and TQ rating and RPMs for the 1990 V6. It appears to have adquateTQ but so so in HP.

Thanks and have an excellent day!