Is my Truck okay?

[cyberpine]

I'm not a mechanic. I'm looking for somebody to tell me if what I'm seeing is typical and and not a big issue with this old 87 C10. I'd like to invest some money on rims and an exhaust and would like to know if I'm might be looking at rebuilds of the engine, tranny and brake systems.

I purchased this 87 C10 about 4 months ago.. test drove the truck .. From what I could tell, it drove great and the body appeared to be in great shape. The truck does not smoke or leak any oil and always starts. The engine is original with 97k miles and a Edelbrok performance intake. It drives stong but I have 3 questions/concerns.

- When I push the engine hard sometimes it pings a little bit, not much, but a little bit? Is this normal and generally what does this mean?
- I took the carpet out and now I can hear a light grinding noise in the engine. With exception of one single time when I felt the transmission slip, the transmission has always been solid.
- Sometimes after a long drive, the brakes stiffen up for a few minutes really bad, but then goes back to normal. It's kinda scary what does this mean?

here's a video (note the pinging at first, the sound of the transmission and when it appears its going to stall at the end in that order)

http://www.youtube.com/watch?v=lg4cCLDsFtY

Thanks for any help or infomation.