Over the last 18 months, we've brought you updates of the new aluminum 409 block being engineered by World Products and Lamar Walden Automotive. Here's the latest on it.

World Products, the noted provider of crankcases, cylinder heads, and intake manifolds, has announced an intriguing, new aluminum replacement engine block for the desirable Chevy 409. Weighting 140 pounds lighter than the original and with the collaboration of long-time 409 tuning wizard Lamar Walden, World Products has resurrected a much-loved engine.

“People desire something different,” ventured Lamar Walden. “They are surrounded by small-blocks, powering everything from race cars to tow trucks. But the 409’s distinctive W-shaped valve covers piques their interest immediately.”
   As with all 409s the block deck is machined at 64 degrees to the cylinder center line, unlike the 90-degree convention of most engines. And the distinctive, embracing appearance of the 409 water pump is retained, as are most of the engine’s external surface areas.
   Inside, however, the new cast aluminum block embraces modern technology. The cylinder bores have been increased from 4.3125 inches to 4.5 inches, allowing the engine to breathe better and to rev faster and higher than its venerable predecessor.
   Further, to accommodate longer stroke lengths the position of the camshaft is raised by .250-inches. GM’s original 409 engine featured a 3.5-inch stroke that could be extended to 4.0 inches. This new World Products’ block permits a stroke length of 4.750 inches, offering a potential displacement of 632 cubic inches. The original 409 when endowed with a 4.0-inch stroke was limited to 482.
   Four-bolt main caps replace the original two-bolt layout, and both the main bearing journals and the rod bearings journals are designed for today’s superior, high-performance bearings. The rod bearings for the original 409 were adequate for greater power output but the mains were not.
   Approximately 25 technical innovations have been incorporated in this new engine block. Walden commented: “Common sense prevailed in the selection of parts; they are now all premium components, readily available, and economic to all pockets.”