RPM question for 88 5ksq

["AMZ" <amz@eskimo.com>]

I have an '88 5ksq.  While traveling down the highway at 70 mph, I noticed
the tach at about 3200 - 3500 rpm.  That, in and of itself, didn't concern
me, but it seemed as though the engine was revving pretty high.  Let me
restate that... it *felt* as though the engine was working harder than it
should.  In 5th, shouldn't it cruise comfortably at 70?

On a more detailed note, does anyone know the proper speed/gear/rpm "bands"
for an '88 5ksq?

Thank you in advance for your reply,
Andrejs