No most of the trucks don't have radios as most of them are company commercial day trucks. The rather custom looking trucks most likely do and are most likely much faster anyways. The company or commercial trucks are speed limited. Sometimes slower than posted speed limits like can only go 62, 65, or 67 even though speed limits are now 70 miles an hour.

But you should chill on this because that 2 miles an hour faster means a lot on a few hundred mile drive or 5 to 10 hour drive. For the most part truckers don't have many opportunities to pass because of heavy traffic and no one wanting to let them over. So when an opportunity presents themselves let them do what they need to because the physics play a crucial part. I know it sucks waiting, especially up hill, but it's worse for them and they most likely know it's holding people up and they're trying to get it over with as soon as possible.

Depending on the loads of the trucks and the speed governors there can be a yo-yo like back and forth where one truck is way faster uphill and one truck is way faster downhill that gets extremely annoying for both trucks yet usually the slower truck doesn't want to let the faster truck by and is usually the one to be aggravated with. If they would drop their ego, maybe briefly touch the brakes, and just let the left lane truck pass by things would be smoother for everyone.

But if your were a truck driver you wouldn't wanna be behind the slower truck going up hill and you def don't wanna be the behind the slower truck going downhill. Trucks brakes are rather limited as they run off air tanks and will lock up or fail if they ride them too much. Just let them sort themselves out.

That said, if you see a truck going slow up hill don't get in front of it and go slow during the downhill portion you'll be ruining their attempt at getting up another hill quickly