You changed three components so it is hard to isolate what caused what. What rpm are you at 1050 degree? Also what boost?
Intercooler- The more boost you run the hotter the air will become pre-intercooler which is when the intercooler will show gains. If you are only running 5-10lbs of boost the intercooler will not show you much benefit like you will see at 25lbs + when you actually have heat in the intake air that needs to be cooled.
manifold- Sometimes the manifold will have higher volume which can reduce exhaust velocity and make a more sluggish spool at lower rpm. This is a tradeoff, because as rpm, boost pressure and drive pressure increase, the increased volume and shape of the manifold can help efficiency and flow. What boost and drive pressure were you at pre-swap and post swap on the same grade? Have you done a WOT run and compared EGT before and after the swap?
Cam- The 188-220 does trap more air at lower rpm which cools down egt. It also opens the exhaust a bit sooner which creates a larger pressure pulse to hit the turbine wheel. Since we open the exhaust a bit sooner, often time at low rpm, in a lugging situation, you might see a small increase in EGT even though there is a more complete burn happening on the power stroke. I would be interested in feedback on a WOT run. If you think this is the case, try adjusting the exhaust lash to .025" and see how that affects egt. If it does nothing, then change the intake lash to .015" and do the same Lug up the hill. If either one of these makes a positive change, then your cam is a bit big for your application. I do not know who spec'd it in, but if you are after low rpm towing/street performance, you might be better off with the 182-214 or the 178-208. the 178-208 will greatly help low rpm performance at the cost of higher rpm performance compared to the 188-220. That being said, it will still outperform the stock cam across the entire rpm range. If you bought from us and we spec'd it in wrong, I will be happy to take the used 188-220 back and trade you into the cam of your choice.
Cheers,
Zach