Always check casting numbers on blocks and heads, and check factory service bulletins before you buy....Or before you call someone a liar

When your searching for a musclecar-even if it's a 1987 Buick Gran National-it's at least 25 years old-most of the other favorites are over 30 or 40 years old. The chance of them being perfectly original is almost nil. You have to remember that these were just cars, that people drove to work, and raced an abused just like you do with your 2006 Mustang GT. If a Do it yourself type mechanic blew the engine on his '67 GTO in 1975-chances are he'd go to a junkyard and yank a 400 out of whatever Big Pontiac was there, throw it in the car over the weekend, and drive it to work on Monday. So, now 37 years later your trying to buy this GTO and are pissed because it has a 400 out of a '72 Catalina.  This happened a lot-a buddy of mine grenaded his 440 Six-Pack Super Bee one night when he missed a shift. I mean, rods out the side of the block, grenaded. We went and got a low-mileage 440 out of a Chrysler Imperial in a junkyard. The only reason he did that instead of accepting a FREE 383 from a buddy was he wanted to keep the tri-power on it and intake manifolds don't interchange on "B" and "RB" engines. He drove it another 3 years before selling it. So, again-now some 30 odd years later some Mopar fan is pissed because it has Six-Pack vin numbers, and the induction system is on the car-but the block and heads say the motor came out of a '75 Imperial. And the owner is swearing that he bought it from the 2nd or 3rd owner. He did, except when my buddy offered the numbers-matching boat anchor to the guy he sold it to 30 years ago-that guy declined. Subsequent owners just assumed or never asked if it was original. Nobodys trying to screw anyone, that's just the way it turned out. On the other hand-a guy may not be lying if he says he has an LT-1 350 in a '76 Camaro, or an LS6 454 in a '68 Chevelle. No, they were never factory built. But long before crate engines became all the rage, you could go to any GM dealer and through the parts department buy a complete LT-1 or LS6 engine, complete with 11.0:1 compression, solid lifters, everything. Until the '80's you could buy the parts to build an L88 427 or an LS7 454 as well. I have a GM Performance Parts catalog from 1989 that advertises all of them. You could also buy a 1973-1980 L82 Corvette engine in short block or long-block form until 1991. So do some checking-the guy may not be a schmuck-he may have a for real LS6 in his Chevelle or El Camino or whatever and you may be getting a screaming deal-so check the block and heads before you call him a lying, cheating SOB. This isn't restricted to Chevrolets. You could buy a Boss 302 engine or a Boss 351 from a Ford dealer as late as 1981. I know, because I worked in a Ford dealer in 1981 and we sold them!!  As late as 1983, when I was working in a Pontiac dealership you could still buy complete Ram Air IV / 455HO heads, and the intake manifold and cam, lifters, pushrods, valve springs etc over the counter. That's because back then-the Big 3 stocked service parts for 20 years. They were pricey, but you could buy them. And-people do stupid shit with cars-especially if they don't have any money at the time-I got a 421HO out of a 66 Gran Prix for free one time, because it spun a bearing, and I gave the guy a running 389 that I had laying around in trade. I spun a bearing on my '68 SS396 El Camino-and swapped in the 327 out of my aun't wrecked Impala because my cousin gave it to me for free. I later sold the 396 to a guy who put it in a '78 Camaro. So when someone says-this car has a special engine-give them the benefit of the doubt and check the numbers-or you might miss out on the deal of the century. Mastermind