Pros of locking the front diff is that you will get better traction out of the turns and off the line

cons are that the turning circle is drastically increased as both the front wheels are driving making it understeer

Cen make a centre diff locker which should fit your front diff. Or you can just use a heavy oil so that it still slips and your turning isn't comprimised.
the diff lockers are very hard on the axles so if you put one in don't run your truck on a paved surface. off-road only

-ben