Another 87 octane/aluminum heads question

You make it too easy with all the detailed numbers! Kinda have to guess with the cam for IVC/ICA, but guessing 240 advertised duration, I get 9.35 for SCR and 8.2 for DCR, so those numbers agree.

Upping the SCR by 1 whole point would increase DCR by about the same. So 9+ DCR does not sound any good at all for regular fuel.

BUT, your higher elevations are helping and lowering that DCR by right at 0.5 points, and even more going to Utah. So, if you will be staying at Odessa's 2900' elevation and higher, then that will help. And conventional thinking is that the AL is good for at least 0.5 points in DCR. (Racer Brown says 1 whole point on his site.)

Since you don't have a great quench gap to preserve (it's at .052" right now), then I might consider the Edelbrocks with the milled 'open' chamber at 65 cc's. Throw in a .051 gasket and now your SCR is now 9.75 and DCR is 8.6 at sea level and 8.1 at your elevation. Or stick with the closed chamber heads and current head gasket and hog 5 cc's or so out of the chambers..... but I am not sure where to take it out of those heads.

IIRC the SpeedPro's have 65 cc chambers in the closed configuration so that might be a head to think about since you just want the AL material, not the highest flow numbers.

Seems like that is in the ballpark to make work with the proper care. Probably a bit of cam retard and thicker head gaskets and timing will get your there. A larger cam would help but you ought to stick with the 114 LSA for fuel economy. Dunno if there is a roller cam with longer ramps to make the ICA later; that used to be done with flat tappet cams. I had a 190@050" advertised intake duration cam in a 351C that had an advertised intake duration of 254 on an LSA of 114 just for that reason: better fuel mileage with a higher CR engine. (It had a DCR of 8.3 with iron heads and would ping a bit on regular, even at 1000' of elevation.)

IMHO, you need to communicate with AJFormS as he has run low octane fuels on DCR's in the mid to upper 8's IIRC.