09/08/2026
RAT billet CNC 4130 chromoly T4 conversion header stub pipes with integral V band!
One thing for sure. The stub pipes that have been available for these engines just plain suck! Even the hand made stainless steel USA made offerings need to be handled delicately to keep their mounting ears from bending. “Install with light torque, use these special washers and safety wire them to hold them on”. That’s what you will be told. Once these bend you have to tighten them, and they bend more until they completely fail. It is a problem that we have fought over and over since 2001. NO MORE!
These RAT stub pipes start life as two chunks of rectangular billet 4130 steel. They are then CNC machined in house at Raby Machine Works into a stub pipe that won’t only forever kill the “bent ear syndrome” but also offers an integral V band attachment point while simultaneously performing the oval port to round transition within the stub pipe. The design also offers an anti- reversion transition at the mid point of the pipe where the two pieces of billet steel are tig welded together by Jake Raby. Once completed the units are heat treated to top off the durability aspect of things. The final step is to surface grind the sealing surfaces perfectly flat. These are developed and manufactured in house at Raby Machine Works from USA sourced materials, using USA made equipment. (Shown here in raw state prior to heat treatment and final surface grinding)
