Not quite accurate
1978 on up Buick V6 engines are even fire!! What Buick did is offset the crank journals to make the engine fire like a V6 at a 120 degree angle. All f us that use a Buick HEI on our GMC V6 engines are from 78 and later even fire engines. Chevrolet really never built a fully even fire V6 out of their 90 degree block, it was a compromise, they didn't offset the rod journal on the crank as much as Buick did figuring it wouldn't weaken the crank as much but even the 4.3 Vortec still had some shake to it in the lower rpm range while the Buicks were as smooth as silk!!
