Thanks for the advice, definitely something to consider
My tank doesn't have a vapor dome, just (if I remember correctly) a 1/4" NTP vent bung on the side at the top left corner. I was looking at something like this overflow tank to help with expansion:
https://www.jegs.com/i/JEGS/555/51145/10002/-1Possibly mount at an incline up between the two rear shock mounts, or vertically in the truck followed by an in-line rollover valve (mounted straight up and down) thinking it will help with fuel slosh (weight of the fuel pushing against a check ball) but still allow fumes to vent and air to enter as the fuel is consumed. Finally, having the vent line run up into the trunk as high up as I can get it (under package tray, above the level of the filler cap) and then back down terminating under the trunk to some type of filter, all the while making sure there isn't a low spot that could collect fuel and act as a "trap" that would cause the system to burp.
