Does anyone know what the bolt length and width should be to go all the way through the frame for an install that doesn't have the captive nuts welded to the frame (cargo van)? I have 3/4" of plywood over the stock metal floor. It then has to get through the frame and then through a custom steel plate I intend to fabricate to distribute the load. Ideally not metric as there are lot more readily available grade 10 bolts in US spec.
Here is what I was told:
7/16 wide grade 10 in lenght of 6" for the four outside bolts that go through the frame. 3" for the center two.
Seems short to me.
Has anyone actually done this that can share the bolt they used please?
and I'm planning on using the 2018 and prior seat mounts as the 2019 ones are hard to come by.
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