I have a Remington 700 BDL with a Leupold VX I 3-9X40 with Leupold STD scope rings that are too high. What size should I order to replace them with? Any help would be appreciated, thanks...

Attached a link to the Leupold Mount Selector. They suggest Low rings for your setup.

Leupold Mount Selector

Thanks, that was what I was looking for.

Its a matter of preference I quess. I like the highest rings I can find and even find the good see through rings very comfortable. Most people hate them.

I would imagine that it would depend on the diameter of the out going portion of the scope itself (50mm etc.), would want that portion to clear the top of the barrel without having to ad shims to the rings.

for optimum accuracy you want your scope mounted as low as possible, low enough but not so low that you cant put your lens caps on. Dm1975 with your setup you should beable to use low rings. rings come in sizes low, med, high, and super high atleast thats how leupold sizes their rings. if your rings say STD size or something of that sort chances are they are med rings.
good luck