air conditioning....yes or no?

I would keep the a/c but your /6 will be struggling to pull out into traffic with the a/c on sucking more power.Either slant six is weak in power...170 - 101hp & 198 - 145hp I would defintely do some power upgrades but be mindful that you may have to upgrade the cooling system if you go overboard. There a lot of /6 guys here that can help you out. Also checkout slantsix.com