Larry, I spent some time looking over my axle because it is apparently obsolete
and critical parts such as brake shoes and magnets are no longer available from
since the original manufacturer has gone out of business. My trailer is an '81
and it has a drop axle mounted below the springs.
The existing clearance is enough for me, but if the axle was reversed
(assuming you can reverse a drop axle), it would raise the trailer 4" or so.
In my case this wouldn't work since the hub assemblies are welded to the axle
and the brakes
would also end up upside down. If your hubs bolt to the axle
you could probably reverse them if you flipped the axle.
Another consideration might be replacing the drop axle with a straight one,
which would probably provide a similar amount of lift. If you already have
a straight axle, you might be able to mount it under the springs rather than
Some other inventive folks on this site have welded spaces under their frames
to increase the clearance.