CdnGMfan wrote:

---

Chevrolet did a low-compression (8.75:1) 327 with a 2-barrel for 1967. It was the base and exclusive V8 engine for the Camaro. A low-compression (8.75:1)  4-barrel version rated at 240 gross h.p. was used in the ½, ¾ & 1-ton Chevrolet & Canadian GMC trucks for 1967 & 1968. It was also offered in 1967 in the big cars but only for the Police Cars. That was also used in Australia. For 1968 that engine was a new offering in the civilian full-sized Chevrolets (Biscayne, Bel Air, Impala, Caprice) plus the  Chevelles & Beaumonts as well and was now rated at 250-gross h.p. through the magic of marketing. Meanwhile the Camaro 327 with the 2-barrel (210 h.p.) continued but now was the new base V8 engine in the 1968 Canadian Pontiacs instead of the 307 like Chevrolet. In the big Pontiacs in 1968 the engine was rated at 210 h.p like the Camaro. The Camaro continued to used that 210-h.p. 327 into the 1969 model year, but sometime early in 1969 it was dropped in favor of the 200-horse 307. For 1969 the Canadian Pontiac big cars switched from the 327 2-barrel to the 350 2-barrel rated at 250 gross horsepower.

 

I hope you are not taking the 1969 Canadian GMC specs from the brochure posted at the Old Car Brochure website; it is wrong as it is actually a 1968 brochure. For 1969 ALL 327s were replaced with 350 versions except for the Camaro base V8 as noted, plus the 327 2-barrel became the new base V8 in the full-size Chevrolet for 1969 (curiously rated at 235-h.p. vs. 210 for the Camaro). Blame that on politics. The optional 255-horse 350 was new for 1969 and was a 9:1 compression 4-barrel. Replacing the 250-horse 327 it was designated LM1 and was offered on Chevelles, Novas, Camaros, big Chevrolets, plus Beaumonts & Acadians. It was dropped mid-year in favor of a 9:1 compression 350 2-barrel known as the L65 that had been the base V8 for Canadian Pontiac big cars since the very start of 1969 production. Literally the LM1 4-barrel and L65 2-barrel were the same engines in every way except for the carburetor & intake manifold, plus the LM1 seemed to get the stronger drivetrain components shared with the high compression L48 while the L65 got the lighter duty components (Saginaw transmissions & 10-bolt rear differentials generally).

 

In Canada the Mackinnon engines did not come with smog pumps even as an option through 1967; after that they were assigned the same way as in 49-states in the U.S. (California was always the exception).

 

There were physical differences in some Mackinnon engines, but for the engines in question during the period specified there really were not. I dont know about casting numbers in particular, but functionally what I have said applies.

 

---

 CAM.............. YOU ARE MY HERO. Where the **** do you come up with all this amazing stuff.