Port lumps aren't that difficult to install, and they have the advantage of somebody else already doing the dyno work to get the shape right. When the GM engineers chose to block the middle of the intake port with a head bolt they certainly didn't have volumetric efficiency in mind. One of these days I'm going to build a hotrod 292, but right now I'm working on an idea to build a 261 engine with NASCAR connecting rods and a 4 3/8" stroke, for a displacement of slightly over 300 cubic inches. All that in a package that closely resembles a 235 unless somebody knows where to look!
Jerry
