Few minor engine problems

[BigBadJohn]

75 c-10 with i believe original 350 and quadrajet carb
First, the carburetor is leaking on the left side (facing the front of the truck)
I guess Ill get a rebuild kit for it. Is it hard to rebuild a quadrajet? Whats it cost to have rebuilt vs doing it yourself

Next, I have to press the sccelerator down in park after starting or will die if I let off gas. Will idle fine after warmed up. Is this from the carburetor leaking? If not what could be causing this?

Last, the engine runs very rought for 2 seconds after turning the ignition off. What usually causes this? Thanks

[Lt.Del]

check for vacuum leaks.  Run-on after shut down could be a vacuum leak, a rough idle also points to a vacuum leak. 

Let her idle and spray some WD40 around hoses and carb and intake gaskets to see if rpm's increase...if so, you found a vacuum leak.

Run-on (dieseling) could also be bad timing.  Set your timing.   You could also have a hot spark plug.

 

I have to press the sccelerator down in park after starting or will die if I let off gas. Will idle fine after warmed up. Is

Check your choke setting.  Should be closed when engine is cold before start up.  Should be open within minutes of starting the engine to allow more air in. 

I'd fix the carb leak if you see it.  Could be the cause of the vacuum leak as well and could start a fire.  If it is the gasket to the intake, they are cheap.