Could have told ya not to call mike c at crane.
Crane AINT crane anymore. They tanked, got bought out by s&s and havnt been the same ever since reopening.
Talked to the same guy in my quest for a competent grinder/cam designer for my sb's. Wouldnt trust him/them to grind a 50cc honda let alone REGRIND a slant cam. I got new (slant) cores from isky, and had lunati grind as forementioned. Did you bother to call either them? Shoot, isky has whatever straight grind you could dream up for your head that flows over 70% ex of the intake. Couldnt possible be due to almost identical port size could it? Think about velocity due to valve size at all? Too big on the exh and it drops, a lot. Which throws your 81% out the window. Be pushing more unspent fuel out the pipes than ever before. Esp without enough ign to burn it.
Will be interesting to see how the big single pattern works out on a split header. 6 into one mp with split grind scavenged better, at least for me. Musta been an isolated incedent. Only tried at least half a doz cams, multiple head configurations, couple of clifford intakes (they dont all work the same) offys, etc. But this was all 10 yrs ago, slant tech must have advanced dramatically since then.
Good luck
