I'm a machinist and do engine work, changing the gear won't be any problem for me. I'd just rather leave the engine alone and spend that time rebuilding something else if I can help it. Hopefully it already has the good gear in it, fingers crossed!
Some of my crap:
1963 C-30 flatbed dually 292/SM420
1965 C-10 LWB fleet 250/column shift 3 speed
1965 C-30 9' stepside 250/SM420/4.10 gears (my DD)
Website I made for my crap:
http://www.66submarine.com 
