Yep and easy to check this is the first thing i'd do. Had this happen recently on another vehicle.
Also if the thermostat does not have a bleed hole in it you can add one to help get the air out.
https://forum.ih8mud.com/threads/fj45-swb-frame-differences.161066/
some talk in there the removable vs. fixed top beds are different so no not all the same
Then with that one being a mix of parts probably equals up to it not fitting
just looks like a bad fit between intake/header, maybe have them machined flat as an assembly. Can try a remflex gasket they are usually pretty good with sealing inconsistencies.
It's been a while since I changed one last but ordered the 23300-69045. Opened it and the filter inside has 23300-66040
Anyone else run into this and is it correct? Don't have the old one off yet to compare it to
Doesn't work for day to day but for stuff sitting outside even just for a long weekend i'd put it on jackstands and remove the tires. Even just the front or back would work. Only takes 10 minutes
Would at least keep someone from hotwiring and...
@TomH I can't turn down a nice 3" vise. These are so cool! Time to make a handle.
@bhsdriller The Athol 6 series are TANKS! The size of the jaw support and the heft of their static jaw above the slide are like no other manufacturer. Great find!