L/b has a better squish chamber = better burn, but the ports as std are not as good a Hemi head.


As far as i'm aware, RST and FRST the only difference is the injector cut outs.



i used to use lean burn's on my old CVH engines, with best results, more torque and power at lower boost, even when spec and c/r was the same, just head swap.

But all my heads are ported and flowed by myself.


on my next build, i will go back to my L/B heads.