You might force a 0 to 30 ohm gauge to "sort of" work with a 0 to 90 ohm sender by using an adapter, but I'll be very surprised if you get a linear output. A variable resistor needs to be constructed to have a certain specific start point and a certain specific end point and a certain sweep arc to be linear. Below you can see where some not very clever worker in China tried to turn a 90 ohm coil into a 30 ohm coil so he could sell it as a 30 ohm sender...and he sort of succeeded---he wiped out enough of it dribbling molten solder on it but there is absolutely no linearity and no accuracy to this mess. Good luck! I'd get a 0 to 30 ohm sender or do what Bill did.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
