These Knucklehead style cylinder heads are precise reproductions of the stock counterparts and show all the small details like cast-in number tags and foundry markings. Thus they make for great replacements for your worn top end or to build a factory look-alike engine. They are manufactured after 1940-1947 heads with large intake ports. The pre-installed, but unmachined valve seats are sized for stock intake and exhaust valves and hardened for the use of today’s unleaded fuels.

Plastic caps for a smooth and safe installation of your new valve stem seals. Three sizes available: green=5/16” (all Evos + intake ironhead Sportster), yellow=11/32” (exhaust only ironhead Sportster), red=3/8” (Pans + Shovels).

Kibblewhite Black Diamond valves are CNC machined from one-piece forgings of EV8 stainless steel. The proprietary Black Diamond multi-stage process treats the shaft to a depth of 0.002” creating a hard, smooth and corrosion resistant surface that cannot flake crack or peel off. The valve tips feature welded-on stellite tips for improved resistance to the impact and abrasive wear of the rocker arms. All versions work with modern lead-free fuels.