I would move the pump next to the tank, if the exhaust is near the tank like mine I wrapped the exhaust with header wrap in that area to keep heat temps down from heating the tank as well, then I got some fuel line insulation wrap from jegs to keep the lines cool and has worked very well for me all though I still have a mechanical pump and also warped the pump with a nice heat blanket like they have for turbos and starters, I also replaced the small amount of rubber hose with stainless with an fittings to a fuel filter and to carb with psi gauge. Also warped headers down about two feet behind fire wall to reduce under hood temps, make sure you have no cracks in headers as this will super heat the engine compartment as well any near by fuel lines. When this happens does your engine begin to run lean and engine temps rise causing oil temps rise to the point of oil thinning and loss of oil pressure then dies or does it not make it to this point? With the fuel upgrades I did on my flathead, in conjunction of relocating my coil and byp*** oil filter away from engine as dwell relocating battery to trunk and added oil cooler I have eliminated all heat issues.
My '38 Ford pickup did the same thing, nearly ran me insane before I figured it out. It would act like it was running out of gas when it had half a tank or so. Turned out the pickup tube inside the tank had a hole rusted in it, when the fuel level got below the hole, the fuel pump was ****ing air. Plugged the old pickup tube where the line went into the tank, ran a new tube through the sending unit mounting plate, hasn't quit on me since.