I've re-read your very first post and there are "flags" in it.
First off hopefully none of the "tons of rust and scale" are not now in the radiator.
Flag #2, a fan that pulls only 1000 will not truly get the job done. Especially in the hot summertime.
I'd also say wait until you get a good guage and see what happens.
I've ran electric fans quite a bit without any problems. I've also had trucks idle, while working on them, for quite a while in the shop and still maintain correct temp. The correct fan is a must whether it is a mechanical fan or an electric!.... and a fan shroud is almost a must on some of these modified vehicles.
