[LS6 RAT]

Here is some proof about what I said in my post above. I called on an ad in Decembers Hemmings Motor News issue, under the Camaro/Chevelle parts section ads. A long time muscle car enthusiast/collector for 30yrs was selling a lot of parts. In his ad he listed an NOS LS6 cam & lifters, I called and he stated that he pulled this camshaft out of a LS6 crate engine bought in the early '80's. I had him read me the stamping on the end of the cam, it was stamped 3144, which is the 3863144 stamping for the part # 3863143. This camshaft has a grooved rear journal. So here is proof that this camshaft was indeed used as the service replacement cam for the original non grooved camshaft part # 3904362 and stamped 3904366.