Great Guy's! I love this Form especially the Joker. I get a laugh about that. You can now google Magical C and this Form pop's up. Okay then on a serious note; In 1969 the first 440 6 Bbl. engine package was produced with a special rods, crank, timing chain, camshaft,valve springs,and intake system. This package was continued in 1970 & 1971. In 1971 the 440 6 Bbl. along with the 426 Hemi were the last truly high performance vehicles produced. Here's another Great!! Fact!! In 1971 B engine performance returned to Grand National Racing. On July 4th 1971, 4 cars with 426 cubic inch versions of the 440 with ported 440 heads were entered in the Daytona Grand National Race and finished 1234. Performance and reliability have always been the trademark of B engines. Thanks for the Magical C guy's, what a hoot! I cant tell you what it means, my speculation is; Dealership Stamped for proof of work being done, meaning (more than likely a recall). I sure loved my GTX it had one of these engines but it was the 4 Bbl. version. But still an RB.