That guy has quite the imagination it seems...
BTW, the MkII 427 "Mystery Motor" from 1963 is a completely different animal, and this thing is definitely not one of them.
This is a MkIV bigblock with little information and a lot of fantasy in the ad.
Oh,O.K. I thought this was the same.
I read this old thread hear from 06.
Sep 18th, 06, 7:49 AM
Yes, you absolutely have missed something here. But don't feel alone, there are MANY, MANY people who do not realize that in 1963 Chev built TWO (2) totally different 427s. One was the Z11 which was a genuine RPO (Regular Production Option). ALTHOUGH, the Z11 option was very little known by the general Chevy buyer, it was a genuine option (of course it was targeted at the serious racers), and anyone who had the money to plop down could go to their local Chevy dealer and special order one. The Z11 option was (as you probably know) a COMPLETE pkg--------------------NOT just an engine. MOST engine options start with the letter L (ie L88, L79, LS6, etc) and MOST pkgs that include multiple components, usually of a performance nature, start with a Z (ie Z11, ZL1, ZL2, etc). The engine which came with the Z11 pkg was a stroked version (basically) of the 409 (or W motor as we know it). And it ONLY came ONE way. To mention a few variations from the regular 409 were, different heads (to include the very first pushrod guide plates), different valve covers (upper outer corners were a little different) ,2-piece intake manifold, modified oil pan, cowl plenum air cleaner, etc.
The 427 "Mystery" engine was a totally different design from anything that had been produced up to that time. And also, different from anything built since. Yes, the 427 resembles a MKIV engine, but it is NOT. Nothing, repeat, nothing from the 63 MKII 427 Mystery engine interchanges with a MKIV engine. The 427 (officially the MKII version) Mystery engine was built rather clandestinely by the Chevy engine (the leader of the pack was Dick Kenaith) engineers and WAS NOT available to the general public! It was "provided" out the back door very secretly through a few sources such as Smokey Yunick to bonefied NASCAR racers such as Junior Johnson, Rex White and others. These engines were "field" installed and tuned and pretty much blew away the competition at the 63 Daytona 500. Because of minimal testing (the testing was actually done by the people who raced them), their longevity generally proved to be less than desired. But they ran great!!! The top brass at GM/Chev got wind of this "Mystery" engine that was doing so well through outside gossip channels and mandated that all development be stopped immediately (another example of the dumpa$$e$ upstairs within GM, they existed then and they exist today). As you have noticed from the pictures above, that 427 Mystery engine "looks" like a 396-454 MKIV engine-------------but it's not!
The VERY FIRST BB family was the MKI-348-409-427(Z11).
The MKII was the 63 427 Mystery engine pictured above.
The MKIII existed ONLY on the drawing board---none were ever built.
The MKIV was, well, we all know the MKIV quite well as the 396-402-427-454 family.
The heritage has continued with the MKV and MKVI (496-502-572).
Now, you know the story."