[rohrt]

Originally Posted by gtohurstjudge

Darth, since the valley pan is a 67 model, it may be that the entire engine
is a 67 model. If so you need to be aware of a possible problem that would result in the
engine having little power. During the 67 model year, Pontiac made a huge batch of
crankshafts with the keyway for the lower timing gear in the wrong place. Rather than
scrap them, which is what Pontiac should have done, they installed a special lower timing
gear on these cranks with the keyway in the wrong place to compensate for the timing error.
Everything was fine till some poor schmuck decided to replace his timing gears and chain
twenty years later with replacement parts with the keyways where they were supposed to be.
The result was an engine with no power and very low compression. I got stung by one of
these cranks on a customer's 67 GTO about fifteen years ago. We changed out the timing components and the car wouldn't get out of it's own way. When we degreed the cam we discovered the keyway on the crank was about ten degrees off where it was supposed to be.
We purchased a lower gear with multiple keyways to get the engine in time. This car had me scratching my head and my balls for quite some time! Ironically, about a month after I solved the problem, an article appeared in High Performance Pontiac magazine talking about the
existence of defective 67 crankshafts. Check the compression on the engine. If it is a GTO
engine it should be at least 175 psi or more. A low compression Lemans engine should be at least 150 psi. The engine I had with the keyway in the wrong place for stock timing gears was reading about 105-110 in every cylinder. Also, as someone pointed out previously, the
sock in the gas tank could be plugged up. The one in my GTO plugged up at 90,000 miles
in 1974, causing lack of power and laying down at high speeds.

That is interesting. First I have ever heard of it.