The best replacement for heads is tails.

The best alternatives to heads are rated as following:
★★★★★  tails
★★★★  feds
★  cast iron
★  aluminum heads
★  black heads
★  iron heads
  mids
  gt40p heads
  double hump heads
  2v heads
  rotary heads
  dill seed
  2006 heads
  white heads
  vortec heads
  #16 heads
  closed chamber heads
  ported iron heads
  289 heads
  tails coin
  closed chamber
  l92 heads
  stock heads
  afr heads
  23 degree heads
  gt 40
  open chamber heads

Your alternative for heads is not listed? Suggest!
Speaking about heads, one probably shouldn't forget about bodies.

Other search terms related to heads and their ratings are:
★★★★★ bodies
★ valves
★ hose
rome
You have in mind a companion for heads and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of heads in all years. Click on graph for more.
heads
tails
feds