i do that EM replace all the time. on 100s of games. it's dumb to put a 30 ohm coil back in place, unless you like "the burn". it's just silly to do that.
on coil substitutions, it's best to start with resistance values. what LTG said frankly is just wrong. resistance is where it's at. It's always better to go to higher resistance. That puts less strain on the system (especially on solid state games.) Lower resistance will give you a strong coil, but there's risk involved in that.
for example on the 25-1000 coil mentioned (from memory) i believe this is about 10 ohms. a more common coil is the 26-1200, which is used in the pop bumpers, and is about (from memory) 14 ohms. This is a good substitution. There will be less strain on the driving TIP transistor. As long as the feature "works", you'll be good. Now if you listened posted advice above, and went in the *other* direction, you could be causing some pretty serious damage. say using a 23-800 (which would follow that ill advised "two step" rule), that coil comes in at 4 ohms. Depending on the programming pulse length, that could cause the driving TIP to smoke very easily, and then you're doing board repair.
look at it this way. think of a coil as a faucet. the higher the resistance, the less water that gets through. if you have a low resistance coil, a lot more current gets drawn. That can be a big deal depending on the application. you can smoke things. But if you use higher resistance, less current (water) goes through. The only risk with that is you may not have enough power to control the device (or clean that pan.)
Let me give another application of this... Early Dataeast games *love* to smoke the left lane kick back coil. The original is an 23-800 coil, and the pulse length driving that coil is too long. The TIP driving transistor loves to bake, and the coil locks on, and burns. I go tired of replacing the coil/transistor on our Time Machine for example. So after a TIP replacement (which burned and shorted), i changed the coil to a 26-1200 (14 ohms). That's significantly less current draw, and i haven't had to deal with a burned coil since. Is the kick back less powerful? Yes it is. But it's still powerful enough to do it's job.
Another thing to remember is coil frame size. Gottlieb and Bally (1987 and prior) used a slightly (1/16") shorter frame size on their "general use" coils (like pop bumpers and slings.) Williams use 1/16" longer. Sometimes this is a problem, sometimes not. But it's something to consider. Usually the leter prefix (at least on williams and bally) specifies the coil frame.
Gottlieb didn't do that generally, they used an "A" for assembly number on nearly all cols, with a sequencial numbering system. For example, a A-9740 coil was designed before an A-16890, in time. For example the 4 digit numbers are all 60s and 70s parts. The 5 digit coils are pretty much 80s and newer. The 3 digit coils are late 40s/early 50s in their design.
There is some science in the "henries" of coils too. That is, if two coils have the same resistance, but different windings/coil wire, are they the same? In terms of the electronics, they are. But in terms of the actual usage, maybe not. The henries will be different, and the coil *could* act differently. But for the most part it's all about the resistance, and that's where you should concentrate your substitutions.