This question is probably best answered by mgmetalworks. My van came with two Sienna seats. I have attached pictures of the bases the previous owner used and the holes he drilled. I am 99% certain the way he set it up was NOT safe.
My question is...can I reinforce the undercarriage where he drilled the holes for these bases or am I better off purchasing the correct bases from MG Metal works that fit in the factory ford approved holes?
If you don't want to spend any more money, those brackets look pretty stout on the seat side. We try to locate as many mounting holes as possible through mulitple layers of body structure (floor, underbody cross members) and use sections of flat bar under the floor at attachment points to distribute load. We also try to use factory threaded holes where ever possible but sometimes they just don't line up with the layout we want.
There is a configuration where our mounts will use two of the factory holes and two drilled holes through one of the body cross members. You could probably get the same result with those brackets with some measuring and drilling.
If you don't want to spend any more money, those brackets look pretty stout on the seat side. We try to locate as many mounting holes as possible through mulitple layers of body structure (floor, underbody cross members) and use sections of flat bar under the floor at attachment points to distribute load. We also try to use factory threaded holes where ever possible but sometimes they just don't line up with the layout we want.
There is a configuration where our mounts will use two of the factory holes and two drilled holes through one of the body cross members. You could probably get the same result with those brackets with some measuring and drilling.
Thanks! Any chance you have any photos of what you are describing? Also, do your bases allow the sienna seats to sit higher? With these bases currently the seats sit a lot lower than the bench seat.
We offer two different heights of mounts. The lower of the two would probably sit a little higher than what you have now. The taller mount is ~3" taller than our lower. see https://base-fab.com for some pics of seats with mounts.
send me a pm with your email and I can send you a pdf with some mounting details