1998 P30 Chevy 454 - Stalling at interstate speeds

I had a Class A on a P30 chassis with the 434 and had the same problems mostly in hot weather, and I tried all the fixes mentioned here.

Took it to Chevy truck mechanic and he said it was common problem,and showed me the reason. The fuel line is routed inside the frame rail next to the exhaust system and it would cause a vapor lock,he re routed the fuel line and the problem was solved.