Is the '79 motor ready to go? or will you be swapping parts off of the '78 onto it? If it is complete and you won't be actually opening up the engine, keeping track of all the critical bolts people have been mentioning above shouldn't be a problem as you won't be removing them, and your project should be really simple.
Sascha Steinway TLCA # 20217
1977 FJ40 "Ripper" (because it shreads!)
1988 FJ62 "Dino" OME, now in the hands of my daughter
2013 F-150 "Black Ops"