Thanks for all the help.
1) I've never used Pyrex at High temps. 450F. Kind of scared they might shatter.
2) I try and follow a new recipe and use what is called for. Then, depending on how it turns out, I'll start changing it.
3) I have a 6", 2-10", 12" cast iron skillets that I normally use. I have an 8" and 9" cake pans rated to 550F and just got a new 8x8 non-stick pan rated to 500F.

I started finding recipes calling for 8" and 9" cast iron skillets and I was not about to buy them. So I ended up with the cake pans. (Fat Daddios brand) Ended up at $3.00 each for the pans. Now I'm finding recipes for 9x9 pans, but for these I'll use a 10" cast iron. I haven't run across any recipes using a 9x13 pan, but I should be able to squeeze that into my 12".

Thanks for the help. One problem. Renolds Wrap website says parchment paper up to 420F. Cornbread is usually baked at 425 to 450F and even 500F. You have no problems at these temps with the parchment paper?

Kind of funny. I'm trying Spider Cake and found out the cake is sticking to the cast iron skillet. I'm thinking 350F is too low for a crust. Plus I also found that the cream is leaving a sticky mess in the skillet. Won't flip out of the skillet. I should try parchment paper in that recipe.