This is the previous setup but it is not only about volumetric flow but about flow velocity. To just take a port and make it larger, you rob yourself of flow velocity (see Bernoulli's equation). Can the L92 heads get there? Probably as with anything else, the right combination is the most important when it comes to power.
My car with L92 heads gained 13rwhp with the Yella Terra 1.85 rockers so I already had a 13rwhp head start on the 60-70rwhp gain people typically see with 230 @ .050" cam swaps (so the cam gains were more like 47-57rwhp). I'd say my heads were worth closer to 35-40rwhp over the stock L92 heads since Tony's FAST 102 porting typically adds 7-10. My L76 already had the FAST 102 on it before. I have not seen anybody's CNC L92 heads gain this kind of power over stock in a 6.0L. Remember, the 4.0" bore of our 6.0L engine shrouds the 2.16 intake valves and hurts their flow potential. A 6.2L with its bigger bore is happier with L92s but it's still not great.
The Mast Black Label heads have stellar flow numbers, but like so many high flowing L92 type heads, the hp numbers don't always live up to the flow numbers. More testing needs to be done on them before there can be a consensus on whether they're substantially better than L92 heads.
My car with L92 heads gained 13rwhp with the Yella Terra 1.85 rockers so I already had a 13rwhp head start on the 60-70rwhp gain people typically see with 230 @ .050" cam swaps (so the cam gains were more like 47-57rwhp). I'd say my heads were worth closer to 35-40rwhp over the stock L92 heads since Tony's FAST 102 porting typically adds 7-10. My L76 already had the FAST 102 on it before. I have not seen anybody's CNC L92 heads gain this kind of power over stock in a 6.0L. Remember, the 4.0" bore of our 6.0L engine shrouds the 2.16 intake valves and hurts their flow potential. A 6.2L with its bigger bore is happier with L92s but it's still not great.
The Mast Black Label heads have stellar flow numbers, but like so many high flowing L92 type heads, the hp numbers don't always live up to the flow numbers. More testing needs to be done on them before there can be a consensus on whether they're substantially better than L92 heads.
Very well but there are still factors that play into it. What size was that cam for 470 with L92s? How great of a port job? You can't take Mikey "Johnny Racer" Heyden's port job and compare it to AFR who have been doing it for however long. Or maybe it was AFR. My point is too many different factors but hey, if cathedral worked for him, great.
