Taller tires on an older trailer?

Hi, folks - it's just me, back again...
A few years ago when I rebuilt my standie trailer ( a 1964 Week-N-Der) I replaced the rotten rubber on it with the 4.80 x 8s that it had on it.
Now, after more than a few thousand miles the tires are fine - but the frame is shot.
As part of putting a new frame under the trailer one thing I want to do is eliminate the swan-neck tongue this thing had on it. This means I need to raise the straight tongue to fit - and what I was planning as part of this (along with doubling the end of the tongue tube) is going to 12-inch trailer tires from the original 8-inchers.
For a brick that is 6 x 8 by 76 inches (or thereabouts) does anyone see the extra height of the tires being a detriment to stability? I have to say on the original rubber this thing towed like a dream - last trip was 1600-odd miles out and back to Nova Scotia behind an ancient Land-Rover.
Anecdotal evidence welcomed... -Al

A few years ago when I rebuilt my standie trailer ( a 1964 Week-N-Der) I replaced the rotten rubber on it with the 4.80 x 8s that it had on it.
Now, after more than a few thousand miles the tires are fine - but the frame is shot.

As part of putting a new frame under the trailer one thing I want to do is eliminate the swan-neck tongue this thing had on it. This means I need to raise the straight tongue to fit - and what I was planning as part of this (along with doubling the end of the tongue tube) is going to 12-inch trailer tires from the original 8-inchers.
For a brick that is 6 x 8 by 76 inches (or thereabouts) does anyone see the extra height of the tires being a detriment to stability? I have to say on the original rubber this thing towed like a dream - last trip was 1600-odd miles out and back to Nova Scotia behind an ancient Land-Rover.
Anecdotal evidence welcomed... -Al