Turbo adapters are probably made by SPD performance and are slightly larger than stock allowing a drop in exhaust pressure and better flow. $120 for the pair I think. The plastic pieces of junk in the intake tubes are just silencers for the turbos. I took mine out prior to installing my k&n I take system and the turbos sounded a little more whiny but probably placebo. I reinstalled them when I put my k&n system in mostly because they said to leave them in place in the instructions and I hear the turbos even more now. Probably attribute that to the increased airflow. With this cold weather my performance has gone up but of course mpgs are down to about 12-14. I’ve got 35s too though
So plastic ones in intake = silencers
Aftermarket adapters = what tbey claim 21hp and 17 torque
Before I flashed the tune I ran the truck with just the turbo adapters. I can tell you they work. The tone of the motor became deeper and seat of the pants the truck definitely felt peppier. The problem is they are quite expensive and tedious to replace as the cross-member, front driveshaft and various other items need to be pulled in order to R&R them. Of course I went all of 2 miles before I pulled over and flashed the truck after but, during that time I was impressed with how the truck felt and sounded with just the adapters in place. I also installed a K&N drop in filter instead of an air intake as I didn't feel like advertising to the dealership there are mods on the truck. MPG's are still in the air as I just did these mods on Wednesday and haven't had a chance to get more than 30 miles on the truck. Now I just wanna pull the silencers to see how much of a difference its going to make. The thing really howls @ 20psi lemme tell ya lol
BTW off topic did you have to go with a lift on the 35's? I'm trying to put a bigger tire on the stock 20's and trying to avoid a lift if possible or at least the smallest one that will allow the truck to clear the 35's