The good news is :
The OP's trailer is placarded for 14 inch tires and not the 13 inch tires that were installed .
Although measurements need to e taken there should be room to install the 205/75r14 and possibly the 215/75r14 .
If there is room for the 215/75r14 ( 1870 # each ) then the Kumho 857 ( 2271 # each ) will also fit .
I raised my boat trailer fenders 1.5 inches to accommodate the 205R14 which I used to replace the original 13 inch wheels and tires .
You may already have that clearance available .
It is a simpler process to raise a single axle trailer than a dual axle .
You might be able to leave the front leaf spring shackle in place and raise the rear leaf spring shackle by 1.5 - 2 inches and gain the necessary 0.75 - 1.0 inches necessary to fit the larger tire .
I increased my tire capacity so much on my boat trailer that I have not carried a spare for a few years .
The spare was in the way at launch/ retrieval time .
I tow my boat trailer to the Sacramento Delta from Bend in 100 degree heat frequently .
I have not had the first sign of trouble with this setup .
These tires do not get any kind of heating because they are working at 60 % of capacity .
