Originally Posted by OVERtheEDGE
just get another set of heads and port them and theres you some more power. junk yard heads. just make sure the truck they come off of runs.
I definately would suggest not doing that. 4.0 heads tend to crack in between the intake/exhuast valves and there's no point in getting JY heads for that very reason. Remember, even with cracked heads it will still run.
Like I said before, I got two BRAND NEW heads for $450 which including valve job, valve seals, and swapping over my valves/valve springs.