Vacuum Questions and A/C Questions

[Mattman2010]

I have a 1980 K10, It had a 250 in it, and I am now trying to put a 350 out of a 1980 K20 in it.

I have the vacuum line from the TH350, and I am not sure where the hose is suppose to go to.



The 350 I am putting it in, did not have a TH350 behind it, it had a SM465 so I am not sure where the vacuum line is suppost to go. Someone was talking about a vacuum port behind the carb.

This one:


It had about a 2 foot vacuum hose that I think hooked up to this black thing that was mounted on the firewall.




What is this thing? Will hooking the transmission up to that vacuum port behind the carb work, or does that black thing need to be hooked up?


Now about the A/C will the compressor off of the 250 work with the 350 if I had all of the right brackets, and all of the right hoses? I have been trying to save it because I was hoping that I could use it on the 350 when I get all of the A/C brackets. Also what would I need to change on it to change it to the new R134a freeon?