Head Comparo

Royce, I'm sure you are correct about the dual plane 2X4 intake. I'll bet that engine will pick up 20+ HP with that setup. At peak power I was pulling 1.4" of vacuum with the Performer RPM and the single 4150 HP carb. Anything over 0.6" or so is leaving power on the table.

I wish I had a set of the new Blue Thunder MR heads. About a year ago I talked to A.T. Francis at Blue Thunder about my intake testing, and he asked me about a head comparison also. We talked about this for a while, and settled on doing a head comparison where I used the same valves, did the same amount of porting work, and compared the Edelbrock heads to the BT MR heads on the dyno. He volunteered to send me a set of heads for this purpose, if I covered the expense of the valves, porting work, assembly, and testing.

I had a set of bare Edelbrock heads already, so I bought two sets of 2.19/1.72 valves for both pair of heads, then took one set with the Edelbrock heads into my shop and had them street/strip ported. These are the heads that are on the 427 I'm currently testing. Then I waited for the Blue Thunder heads. Unfortunately, I am still waiting. I've called BT a couple of times on this, but have had to leave a message, and have received no response. Maybe he forgot, or changed his mind, or something...

In any case, at some point I'll probably buy a set and run the head comparison test. But I have lots of Edelbrock heads here, so for now all my testing will be using the Edelbrock heads.

Jay Brown
1968 Shelby GT 500 Convertible, 492" 667 HP FE
1969 R code Mach 1, 490" supercharged FE, 9.35 @ 151.20, 2007 Drag Week Runner Up, Power Adder Big Block
2005 Ford GT, 2006 Drag Week Winner, 12.0 Daily Driver
1969 Ford Galaxie XL, 460 (Ho Hum....)
1964 Ford Galaxie 500, 510" SOHC