in 67 by offering a 2barrel, standard V8. GTO became a series, like the Impala SS. I don't think this stayed that way, though. I just remember a 2bbl V8 in 67. As for the 61, I was a 15 year old car junkie, and my best friend's cousin had just bought a nearly new 61 Impala coupe, with the 350 horse 348 and 4speed. This was in the fall of 61, and the 62s had just come out. I don't think it was an SS though-could you get that engine in a non SS car? Anyway, I was smitten with that car, and really liked the 61s for their crisper, leaner look over the 59-60s. Oh what I would have given to have that car.
Well, the 2-barrel was an option on GTOs in the late '60s. Other car makers offered this package in their intermediates (and even ponies) although not necessarily in their musclecars. Lots of cubic inches, high compression, small carb and tall gears, all for better fuel economy. These engines were torquey enough to pull economy 2.56 or 2.41 gears. I know Pontiac had been offering this package on their fullsize cars since at least 1959. Olds called it the Turnpike Cruiser option on the Cutlass.
Yes, you could get the three deuce 348 in a non-SS car. I think only the 409 was exclusive to the SS. No 409 Biscaynes in '61, I guess. Hi-perf 348s are expensive so it looks like lots of guys remember them and show it with their wallets. I got my '61 convertible 348/250 four speed for $250 in 1971, drove the wheels off it and basically gave it away a few years later.
#48 of 54 My favorite cars of the '50s were the 300s....
Apr 30, 2002 (9:48 am)
Didn't think much of the 60s cars, tho.
#49 of 54 Z11 chevy engine Nascar: Speedshift
Jun 11, 2002 (8:20 am)
Reading your post about the 1963 engine the Z11 409-427. Chevrolet made two seperate engines for racing purposes back in 63'. The Z11 version was strictly for drag racing. I believe 56 or 57 lightweight Impalas were made for this purpose. The 427 version for Nascar was called the (427 mystery motor) it was developed a little differently then the Z11 and was offered to I believe 5 or 6 racing teams at the time. Junior Johnson was leading the Daytona 500 when his (427)engine blew and the reliability of the rest was not up to par. I believe shortly after the Daytona 500 GM pulled the plug on factory support and that was the end of the Z11 for drag racing and the Mystery Motor for Nascar.
So the Z11 and "mystery engine" are different engines. It makes sense. The drag engine would be built for peak output and the NASCAR engine for sustained output. Probably the cam was different and certainly the carburetion--NASCAR didn't allow more than one carb at that time.
IIRC that strategy worked a lot better in drag racing, where the Z11s were very strong, than in NASCAR. The 409's bottom end obviously wasn't up to coping with the increased power over the long haul. That has to be why the 396's main journals are substantially larger than the 409's, although a modified 396 crank can be used to stroke the 409.
There isn't a whole lot of information on the Z11/mystery engine, at least in my sources. Sounds like you're into W motors.