Hi S.,
Boy, can I relate to your problem. All three of my boys have gone through this stage. AAAUUGHHH! It's tough! Is he still taking a mid-day nap? I had to stop giving my three year old naps. By 7:00pm he is so tired and ready for bed. I read him a story, brush his teeth and give him lots of kisses. He's usually asleep in 10 minutes.
Also, when kids stay up too late their adrenaline goes through the roof and that really messes with their sleep cycles. You really have to stay consistent!!!!!!!!! KEEP TO YOUR BEDTIME ROUTING LIKE GLUE! It doesn't have to be anything big. I am the sleep Nazi. As soon as the clock hits 8:00 pm ALL my kids better be on their way to bed. It's not easy, but if they don't get enough sleep they are sooooooo crabby the next day.
Boys need that physical activity. It's like they run on batteries and need to run them down before they can mentally calm down. Sometimes, after dinner we'll turn on some funny music and dance like idiots. After about 30 minutes they start to wind down.
I used to have to stay in my kids room and sing them a few songs or rub their feet or back. That helps to calm them down, too. I hope some of these suggestions help. Try to stay sane even if it's hard. Good luck!