the master might be in bypass.
if not,
nine times outta ten, a shifting issue like this is,
http://www.marlincrawler.com/transmi...ver-ball-seats
reverse is always picky. normal.... in the interim, try putting it into first *just* b4 u come to a stop. or go to second first, then first.
your 20 or 22 motor wont do much better than that flat out. long stroke. but it's still just as capable 4x4ing as the V6. in some cases better. it's lighter and has a lower center of gravity.
there is an option/upgrade for your four banger,
http://www.lcengineering.com/
20 heads, cam, and headers, with msd ignition.
you'll get a usable 6500 rpms out of it after that.
for any mods, you should read this,
http://www.pirate4x4.com/forum/showthread.php?t=775780
owner 93 toy pu 4x4 2"lift 33s.