92 Roadmaster 350 5.7L bucks and loses power

In addition, when this happens the gas pedal stiffens and becomes harder to compress. I also get a slight hint of an oil smell when the vents are open.

While you say you have replaced tons of parts wondering if have checked the connections from your engine block to ground. You have some things happening that would indicate a possible loose ground connection. The stiff pedal could possible related to a binding throttle cable or the cruise control linkage binding up. Keep us posted after you check these things out.

I have checked all the ground connections, brushed off corrosion and replaced the few that were in bad shape. It acts like an electrical issue (since it's only periodical, and worsens when raining). I haven't had cruise control at all in the year I've owned the car since the ABS control module is bad, and I haven't found a replacement. I will be checking wires to the fuel delivery system and grounds when I get home in a couple of weeks, I suspect mouse damage