I have an 88 4Runner that is missing most of the dash screws, all of which seem to be the same size? Anyone have a diagram or know what size these screws are so I can get a bucket of backups?

 

I think I used #10 x 3/4" and #10 x 1/2" when In reassembled my dash parts. Used a few #8 size as well. I bought a variety pack of car trim screws from Ebay before I started. Worked great as dash is tight and rattle free.

 

I have bags and bags of original hardware. I grab everything I can when I go to the junkyards. The you-pull places never charge for nuts and bolts.

 

Yep, I even wander over to the Toyota passenger cars from the 90's and remove all the decent screws and yellow bolts that I can easily access.
Wish I had been more cognizant of JIS ages ago. Would have buggered up less screws.
I've bought a few aftermarket screws early on for the interior. They're never quite the same. Though, if the hole has gotten slightly hogged out than the aftermarket ones sometimes are the better choice.