My son was diagnosed with Sensory Processing Disorder (SPD) when he was 3, no autism. Here are some things that I recommend because they helped us.
Start with The Out-of-Sync Child, great read. Then move to The Out-of_Sync Child Has Fun for pratical do at home ideas. If you feel his sensory issues are going to have broader implications for when he starts school, then I strongly recommend getting an eval done by an OT with sensory experience. The Children's Hospital network has some good ones. If you seek OT, make sure you tell them that you want to learn things that would be good activities at home. I observed every session from a side room and the therapist would give me summary on techniques at the end of each session.
Also it sounds like he craves a lot of oral stimulation. Check out The Autism Shop (online or go visit them in Hopkins, MN) , they have a bunch of chewy sticks and other great sensory chew items http://www.autismshop.com/store/home.php?cat=338
Does he actively avoid touching certain things with his hands? If so, start introducing some activities that encourage use of his hands. Sensory issues can have a huge effect on fine motor development and writing skills in school (this has been my son's battle).
Get him to talk with you about what he is feeling at different times. Helping kids put words to what they sense can help them develop a better understanding.
Good luck :)