Heres a what would you do moment. Should I go out and get a rebuilt longblock 351W or should I go get a shortblock and add a set of heads to it? I wont go hog-wild on a set of AFR or Trickflow but something that breathes a little better than stock.
One advantage to buying a longblock is you dont have to worry about piston-to-valve clearance, selecting correct pushrod length, or adjusting valves (even though you might want to check valve adjustment before startup). Now, all of this stuff can be accomplished with the correct research, etc. But I am just talking from a convenience standpoint. If you have the extra few $$ to go that route, that would be preferable. I just went through the same dilema because I just purchased a 331 for my 5.0 vert and I went the longblock route. It was about the same price as shopping the top end of the motor myself and it came all assembled.