J par, the extra 10*’s (or more) of exhaust duration was done in the old days to use with stock heads that had exhaust flow in dismally low flow specs in order to help the engine breath in a fresh air and fuel charge better. The more efficient the exhaust port, the less extra exhaust duration is needed.
Now where this can apply to you would be a mystery to me since,
1: I’m not familiar with your build and it’s specs.
2: The actual and ultimate goal of the build is.
Let it suffice to say that there is a sought after intake to exhaust port flow balance being chased after to help the engine breath in and out for a more efficient engine in the target build. It was something in the 70 something percentage range. I do not remember this balance number right now. I’m sure PRH can tell you in greater detail the balance ratio and how and where it applies best for you personally and in general for the readers learning something new.
The better the head, the less of a split is needed. I’m not sure if adding in the mention of a reverse split seen on the HEMI applies, but it is interesting that I have seen this on HEMI builds before.
To much exhaust duration can actually hurt engine performance. Over scavenging can actually be bad. I know it sounds weird, but that’s just the way it is.
If you have a good set of heads and good breathing in and out of the engine, even a single pattern cam can perform really really well as anyone noticed over the years the split pattern cams have there split duration figures get smaller? (AKA Less exhaust duration.)
AIN’T THAT THE TRUTH!!
WOW! I haven’t seen that in a long time but that does have some revealing information. Good idea linking that. And now I know why I liked that solid purple cam so much that I got it again.
Hey! If it fits the goal, use it.
All hail, his highness, "Kingwillrun" or be scorned and lied about with his twisting of words and meanings brought to you by the mean girls debate club he is in.