Clunk while accelerating.

Only putting on one stock sized tire has probably damaged either a U-Joint, the differential or the transfer case. Only way to tell for sure is to put it up in the air and check for damage. The reason is that the different sized tires rotate at different speeds. This causes the various parts to turn at different speeds relative to each other and that can easily do damage, especially on a vehicle that already has high mileage. I hope it turns out to be something like a mount or just a U-Joint.

Oh and keep the spare tires handy. Unless you live in an area with no pot holes or rough pavement, you will be using them more. The thin sidewalls on tires that will fit your vehicle with 24 inch rims are going to take a beating.