Saved a trip to AutoZone. :)
Update: ended up needing to scale the pins to 92% on X & Y. They're still a tight fit, but I have two of them holding up the back end of the splash shield (?) under the engine on my car. A few light hammer taps to each was all it took, and if I have to drill them out in the future, I can always print more (made 4 to start with when I only needed 2).
Supports (touching the bed only) needed to deal with the recesses in the main body.