I agree with @Cory S . If you had a stick maybe but the 10 speed gearing is probably really steep in 1st and 2nd gear already. If you have a friend with 26” drag radials maybe you could borrow them for a pass before springing for them and finding out it’s not a good fit.
I looked up 235 50 18 overall diameter which is 27.3,
If I were to change to 235 55 18 OD is 28.2
Calculate 27.3 divided by 28.2 whis is equal to 0.9680
Your speedometer will read lower with the 55 series tires. At 60 mph your dash speedometer will read 58.1 and your odometer will accumulate milage lower by the same factor.
The overall vehicle gear ratio is changed by the same factor.
doesn't et as well typically "if" radials are working, if the radials aren't holding, then a slick / bias that is bitting and more forgiving will get you better et