Hot Fuel Lines
Not to be a stick in the mud but it looks like you have created other issues for yourself also. I notice you have a driveshaft loop installed which could mean time at the track. I also notice that you have an automatic transmission. I wont quote nhra rules (maybe you don't run at sanctioned tracks) But I would suggest taking a look at the fuel line rules, not only so you meet rules if you need to, but also because some of them make sense.
On the other side. I don't see how you are generating that kind of heat in your fuel line. You would almost have to have a couple of feet of your line damn near laying on your exhaust to get there. When you get the 140+ reading. Did you take a tank reading? I think your heating your fuel through the pump and line and maybe picking up some exhaust heat and then cycling it back to the tank. Pressure creates heat. Over pressure creates a lot of heat. If your running a super high pressure pump and cycling most of it back to the tank and then only pulling what you need from the regulator to run what? Something around 6 or 7 pounds pressure? Your fuel gets hotter and hotter every time it cycles. And I still don't read that as vapor lock. You have to heat the fuel to the vapor point to create that issue. I'm not seeing it.