what's the width of the 24" wheel...._____/35-24? If it's also a 305 the difference will be about 3/4". here's something to kinda go by.
305/55-20s are about 33.2" tall.
305/35-24s are about 32.4" tall.
there might a very small difference between manufacturers. as a comparison the stock 275/60-20 are 33" tall mathmatically but they actually don't measure out that tall with a tape.