Well I have never heard of the Sailin 637 tire. Our 04 HH came with GY G614 the sorriest tires I ever had what did not blow up only lasted 40,000 miles. So I started looking around for a different tire the GY G614 was the only G rated tire out there so after first blow up got a new one. Had another blow out but it took out the valve stem on other tire so I needed two tires. Called GS road service first guy wanted to give me E tires I said no. GS called #2 he would not get me a G614 either but he said on the logging were using the hankook F19 750r16 a 14ply same as G tire & they had good luck with them - it was take them or set there. I liked them & ended up put F19 on the other side. When I traded off our rig had 50,000 miles on the first two tires & they still looked like new great tires. Next time you are in a big truck stop look around at all the hankook tires on big rigs. I am replacing the tires on my 07 3500 Mega cab drw rwd Dodge. I could only find two tires with a 70,000 mile rating michelin & hankook in a LT235/80R17. With hankook tires I can save $400. Like I said earlier Look at all the hankook tires on big rigs if they did not make good tires they would not run them. So if you need to replace your GY G614 you may want to look at the hankook F19 750r16. Oh yes always have them balance all tires even on your rig.
red