Copy and Photos by Jon Mikelonis

Introduction
Everyday that passes by leaves a smaller chance to score a working man's deal on a pair of 429CJ, SCJ, or Police Interceptor heads for a street smart 385-series Ford buildup. It's true that owning a pair will make great conversation among fellow enthusiasts. Practically speaking however, it doesn't make sense to hunt down and pay for a pair of these now obscure factory heads when mainstream 429 and 460 heads perform quite well for street applications. Furthermore, aftermarket aluminum offerings have long improved on the original design's shortcomings and depending on where you allocate your coin, they can fit a BBF buildup's budget quite well.

FordMuscle originally intended to optimize a pair of standard '73 429 castings (D2VE-AA) for our Streetwise 460. After all, with a 2.09" intake valve and 1.66" exhaust valve, standard is not a bad thing when it comes to the 385-series cylinder head. Since we saved some cash when we scored a low mileage bottom-end, we were able to restructure our budget for top-end power producing speed parts. Edelbrock's affordably priced and fully assembled Performer RPM 460 Aluminum Cylinder Head peaked our interest with a 2.19" intake and 1.76" exhaust valve. Out of the box convenience, streetable runner and chamber dimensions, and the opportunity to shed a few pounds off our project car contributed to our decision go with Edelbrock's offering. In the Performer RPM line, Edelbrock offers two head designs for the 385-series motor. Low octane pump gas and bottom end torque were critical requirements so we chose the more street friendly casting. Part number 60669. This head uses a 95cc combustion chamber and 292cc smaller intake runner.

Flow Testing
In order to found out what a $1760.00 investment was going to yield in flow performance, we took both our factory 429 head and Performer RPM head to Cylinder Head Dynamics of Tracy, California. Paul Widger used his Super Flow 600 on the D2VE-AA casting to create a baseline for us to compare the flow performance of the Edelbrock head. Both heads were measured using a 4.50" bore, a critical figure that Paul says is often absent from documentation that reports flow data. Of course we expected a great increase in flow over the factory iron head considering Edelbrock's increased valve size, but what else might a flow test uncover?

By studying the flow data between these two heads you'll see that the factory 429 head flows relatively well on the intake side. Even in unmodified and neglected form, the stock casting flowed an average of 216 cfm between .200" and .500" lift. The Performer RPM head flowed an average of 229 cfm between the same lift range. Well you might be asking yourself at this point, other than the weight reduction, what is the significant advantage of the Performer RPM 460 head? As you will discover in the following analysis and Q & A, the answer lies in the exhaust data.