Changing a head gasket on a 60 isn't a toooo difficult but if you've never removed an engine head before, its going to take awhile. Do you have a garage where the truck can be disassembled for a week? Do you have the tools, (mostly wrenches) to tackle the job? There is a 50/50 chance that the head gasket failure also cracked the head. When the head is off, have it professionally inspected by a machine shop for cracks. This is also the right time to have a valve job done. Are you in the Denver area?
'03 KTM 450EXC
"If you know what you're doing, then you aren't learning anything." - A. Lincoln