There used to be a company called Clifford Research, that made parts for 6 cylinder inline motors, only. They can help with the 235. I will tell you this, too. The 235 in that year, put out a bit more HP, as an automatic, version, over the stick shift model. You may want to modify the suspension, as well. Art Morrison, in Washington state, has a specialty line for your rig, as well.
When you will be sustaining a speed of over 45 mph
Tires are out of balance ( maybe ) A bad u-joint in the driveshaft will cause it too. Check these things.
55 mph
146 mph (235 km/h)
1 mph = 1.609344 kph378/1.609344 = 235 mph
Several things could cause that: Worn shocks/struts Worn front end parts Tires out of balance Drive shaft out of balance Loose wheel
While I have not tried it in a 2007 Chevy Pickup yet, I have tried it in a 2006 2500 with a Duramax. (On a closed course with a professional driver, of course). It is limited to 100 mph. I have also driven many other Chevy trucks from 1999-2006, and they were all limited to 100 mph as well. Usually this is done by the manufacture based on tire speed rating.
If you had 235 / 75 / 15 tires and switched to 235 / 60 / 15 tires : When your speedometer read 60 MPH you would actually be travelling at 54.2 MPH ( if that's what you are asking ? )
You can but you should not. The 235/85-16 tire will be way too tall and will have a diameter that is 2.22" larger. This will cause your speedometer to be 4.2 mph too slow at 60 mph. This is not a good swap.
120 mph
About 4 hr 15 min.
It depends on the vehicle. The 235 75 17 is a slightly taller tire so you may want to look to see if you have enough clearance in your wheel wells. I believe around an inch taller.Your speedometer may read 1 or 2 mph slower then what you are actually doing also. It reads 58 mph when your actually going 60 mph for example. It just depends on how accurate your speedo was originally.