What if BB never lines up with housing pointer
AT SAME TIME piston #1 is at highest position (highest compression)?
That's impossible, unless somebody has managed to bolt the flywheel on in the wrong position, and that would require some re-drilling of bolt holes. It's also extremely difficult to get the distributor 180 degrees out of time unless you ignore the compression pressure. To build pressure, both valves MUST be closed, so if the piston is coming up the cylinder on the exhaust stroke, no pressure can be developed because the exhaust valve is open.
If you want to be 100% sure the #1 cylinder is on compression, take the valve cover off, and watch the valve rocker arms on the #6 cylinder. (NOT #1) The exhaust valve rocker is the last one in line. Turn the engine, and watch as the rocker arm moves and the valve spring compresses. The valve will reach its maximum open point, and start to close (spring begins to relax). Just as the exhaust valve closes, the intake valve will start to open. (second valve from the back).
At this point, the #1 cylinder will be at top dead center on the compression stroke, ready for the spark plug to fire. Even if the timing marks happen to be inaccurate, an engine that's timed to fire the #1 plug when the #6 cylinder is in the "split overlap" or "rocking" position will run- - - -no doubt about it! BTW, #1 and #6 are "companion cylinders" on both 6 cylinder and V-8 Chevy engines.
Jerry
