i have a 93 pickup 22re street rv cam and head lc header exhaust k&n filter. electrec fan. 160degree stat

When am at idle the the engine stays cool just fine. its when i'm driving on a hot day 80 and above about 3k on the ttach my engine coolant temp rises to imbeteen quarter and half way then half and and a little past. i have to have the engine at rest like at a stop light for the temp to finally cool down and it drops fast. there is no fluid comimg from the weep whole on the pump. there is fluid in the resevoir. and it has been burped sinsce the last coolant change. about two months ago. i also can not use the aircandition cause it rises the temp a quarter bar more.
this all happens driveing on hwy. the hoses replaced with toyota hoses a year ago. wgat are ya'lls thoughts