Sputtering and Surging??

[muddpile]

Last night I was coming home from a parts run, and when I got up to about 70mph, the truck started bogging, sputtering, etc. It kinda revved down like it was going to stall, but never did. The closer I got to home, the lower speed the truck had to be going for it to do it. 50mph was my average speed for the last hour (nearing 40mph as I got about 15 minutes away). It sounded like a lack of fuel, but I'm not sure. What would cause this? I was thinking fuel filter, but haven't checked yet. Before I look, where is the fuel filter located? The truck is a 72 with an HEI 350 4 barrel out of an 80s burban. Thanks!