Found it! From a March 26 post by our own big Al, as told by Skip:
Guys,
This is what I know and believe about the crossed flag 427 emblems. These are GM, not repro, and went on the 66 and 67 full size cars (Impala, Biscayne, Caprice) that were equipped with the optional 427 engine. I remember seeing no optioned 2 door Biscaynes with only the L72 427-425HP and Muncie 4 speed,4.88 posi axle, strictly for racing. These cars had the emblems on them, as well as the well optioned Caprice with the L36 385 HP 427 engine.
Around this era, (1966 and 67) some high performance minded dealers, such as Balwin and Yenko, offered their customers( for a high performance price) the opportunity to have a 427 A body Chevelle. GM had a strict corporate policy at the time about no A body having over 400 cubic inch displacement coming out of the factory. The GTOs had 389s,The 442's had 400 cubic inch motors, and even Buick had the A body Gran Sport with the 401 (they cheated by 1)nailhead engine. Anyway, these dealers would order L72(427-425HP) shortblocks and Chevelle
Supersports with the L78 396-375HP engine. Now these two engines were practically identical(except for the shortblock) and used the same heads,intake,carburators, camshaft, etc.It was simply a matter of exchanging the
shortblocks, and using the existing components of the L78 396 engine on the L72
427 shortblock. For a little extra, if the customer wanted to advertise, the crossed
flag 427 emblems(a mandatory stock item) were added as well. For 1967, GM bowed under Federal government anti high performance pressure , and even cancelled the L78 option for the Chevelle. They also cancelled the tripower options that were available in 1966 on the GTOs and 442s, and had been planned on the Chevelle SuperSports for 1967 in two versions,L64 and L67. One was going to have
square port heads for the L78, the other oval port heads for the L34. No HP ratings
were ever released. I built a prototype 1967 Chevelle SS tripower according to what was in the Chevelle assembly manual, but that's another story. Anyway, a lot of high performance dealers were up in arms about this anti high performance policy, so they and GM's central office conjoured up the COPO plan. (Central Office Production Order)A minimum of 500 units were needed to make the order happen,(kinda like a fleet order) and starting in late May of 1967, 500 1967 Chevelle SS 396s with the L78 engines were ordered for these various high performance dealers. Most of these were low optioned models for racing purposes only. Another 112 L78s made it through production as well.Many of these 500 L78 Chevelles had the L78 396 replaced by the L72 427 to satisfy the customer's need for speed. This was a slick
way to bypass GM's anti-racing policy. Oldsmobile also did this with the 1968 Hurst
Oldsmobile, using the 455 cubic inch engine. These all went to Hurst. It wasn't until
1970 that GM allowed bigger engines in their A bodies. Hello LS6 454! As a part of all this, that is why a original matching numbers 1967 L78 is so rare today.I've documented only about 15 that still exist. I just documented another one in TN, that was inherited from the owner's grandfather. He was 40 years old when he ordered it to tow his boat.The grandson didn't know what he has, and he E-mailed me for info on the car. When he sent me all the numbers, the hair on the back of my neck stood up. It's a real one, and I told him what he had.( No, he's not ready to sell it yet, to sentimental)They either had the engines swapped, or didn't survive the drag racing.
Another interesting question is what happened to all those swapped out L78 blocks???Sorry to be so long winded, but I hope this helps clear up the mystery of the crossed flag 427 turbo-jet emblems.
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[This message has been edited by Al (edited 03-26-99).]
John Walker