50HP Bolt-On Cylinder Heads for a 351W Engine

We bolt Edelbrock's new XT cylinder heads and top end kit on a weak 351W in a Ranchero and see what it's worth.While performing EFI dyno testing on our '67 Ranchero with the Powerjection system from Professional Products (Nov. '08), we noted that the little $2,000 351W made respectable power with good torque numbers despite being composed mainly of stock Ford parts from various generations. However, it began to run out of steam earlier than we had anticipated. The dyno chart showed that it pulled strong until about 4,400 rpm before peaking at 4,600 and running out of breath. Considering our Crane roller conversion cam featured 0.525/0.542 valve lift with 212/220 duration at 0.050, we were expecting numbers to peak somewhere in the 5,000- to 5,500-rpm range. With an easy 7,000 miles on the long-block, we knew wear wasn't to blame. Our gut reaction was to lay fault on the tiny valves in the GT-40P cylinder heads that were designed to give 5.0 Explorers some low-end kick, not help cammed 5.8s breathe on the top end.


Photo Gallery: We Install Edelbrock's New XT Cylinder Heads in a 351W Engine - Hot Rod Magazine

Photo Gallery: We Install Edelbrock's New XT Cylinder Heads in a 351W Engine - Hot Rod Magazine


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