Hey Guys.
I ain't a Mopar guy since my dad finally got rid of a 1970 Chrysler rolling disaster, but your thread has been very interesting.
I called up Rust-Oleum tech support, and according to them, the Tremclad is made by a company called Tremco and is being phased out. They gave me the Canadian phone number for Rusto-Oleum. They also said there was no direct equivalent for it in the US. Now, it is entirely possible they don't know what they are talking about, but there you have it.
Also note that on this page:
http://www.rustoleum.com/product.asp?frm_product_id=551&SBL=5
the Tremco is described as "Farm Equipment Rust Paint" and this page:
http://www.rustoleum.com/Product.asp?frm_product_id=18&SBL=1
says "Protective Enamel." This page:
http://www.rustoleum.com/product.asp?frm_product_id=36&SBL=1
has Rust-Oleum farm equipment paint but with a much smaller color selection. Being in the private label industry myself, I would also suspect that it may be the same as sold at Tractor Supply under their own label, as TSC certainly does not make their own paint.

So, what's the bottom line? I would venture to say that the stuff sold at Wally World as Rust-Oleum Protective Enamel is not the same as Tremclad and may be why it is not drying as hard or behaving differently. Just my guess.

Dr.Hess