Hello BH
On a normally aspirated FE, that head is fine stretched mildly past the OEM power level, and we were early to increase the valve sizes to the CJ , or larger valves, and then fully port them.
Here we have a different thing,,,,a lot of boost, So it is like this, 2 things to bear in mind
1) An open plenum blower manifold delivers fuel and air, every 90 degrees to the cylinders, by, migrating the fuel/air charge down the firing order,,,1542 63 78 If you draw a plan and watch the distance the fuel/air travels, it goes 1 to its neighbore, 5, then all the way back to 4, back most of the way forward for 2, sideways to 6 and so on......7 and 8 often communicate due to fuel puddling on the floor of the intake
A goal is to maintain charge homogeneity,,,,,all engines like that, a fine, well mixed fuel air mix...
So how can we decrease fuel separation, and spped up the charge? Reduce the port or valve size. Kind of like a hose and a high pressure nozzle on the end.
The high pressure nozzle speeds up the flow to the point where the port stalls, and often, helps mix the fuel
Next thing is this, NITRO, is unlike race gas(Except the new franken fuels) in that it bears or brings along it's own Oxygen. So here, you have an intake valve that is smaller than a cammer, sure, it is not 2 1/4, it is 390 ish, 2 1/32 or 2 3/32 basically but guess what?
From about 1960, until today, the 354 and 392 Dodges, and the 417 Donovan, which is a better version of a 392 pushrod HEMI, flew, flat flew, with the famous 2 and 2 combo.
The heads used to win all of those races, in Funny car, and Dragster were DONOVAN stainless valves, for fuel use, and you sized the heads to have a 2 '' intake, and a 2 '' exhaust. A 2'' intake valve, in an iron head, or a alloy one, later, went 200 MPH, then 210, 220, 230. and beyond. Shucks, we pushed a 392 with 354 heads and 2 by 2's, over 234 MPH 15 years ago at the reunion.
I recall 2 and 2's getting to around 239 MPH in the 1/4 so these heads have potential due to the blower, fuel, and use.
I understand how you feel.
We must note, to the SOHCS legendary status, and all of those records and wins,,,,,,by 1965-6, the cammers huge ports, huge intake valves, that were super light, and the SOHC cam genius, the FE started mowing the Dodge bows over, 1 by 1. As we shared elsewhere,,,,,,wwhen a Dodge was close to hurting itself around 7000 to 7500 RPM, thise cammers would charge past them out the back door, winging it 8500 to 9000 all day long
You are definietly on to something though, one huge trick to get the modern Nostalgia engines down in to the 550s, and up to around 270 MPH,,,,,is abandoning the 2 by 2's. 20 years ago, we developed a 2 1/4, titanium, 5/16 stem intake package, with a 1.94 exhaust, flowed them again and again, ran them and quickly started beating a lot of guys,
These style heads, at only 397 CID, well,,,this is kind of secret,,,,but what the heck, you guys shoot for this number some day, and we'll all laugh.
I have helped spin a little 397,,,,,around 10,500 RPM
550 ish lift,,,,strong steel rollers, fat ISKY pushrods, stock style iron DONOVAN rocker arms,,,great springs,,,3 coils,,,titanium retainers, 10 deg locks, etc
Always fun
The 390 406 heads ran on fuel in the ealry 60s, in a Dragmaster or K88 style chassis,,,,a short rail, well over 200 on a good day
Nice question, lets go burn some FE's down on fuel soon
We seriously believe that we could get a 390, with billet caps probably, a good crank, big rods, etc, to 230 MPH with some work....
Many of us would love to hand that back to a few old 'magazine' guys that labelled a 390, well, not so fast..WRONG...HAHA.....Just do it up FORD Hi Po style,,,,
Kindly
T
