Newbie with a question

[76GMCK15]

Hello

I'm new to posting to this forum, but i have been reading posts for a long time. I have been able to do lots of work on my truck because of this formum. I just want to thank everyone for that. I am having a problem with the upper radiator hose getting a huge amount of pressure in it when the truck gets warmed up. The intake must be getting hot also, because the fuel starts to boilover. The temp guage says the truck is not hot. The temp sender unit is new. The radiator cap is new. Could the radiator cap be bad? Do I have air trapped in the intake? Any help would be great.

Thanks