To confirm you're at TDC on either #1 or #6 cylinder, the timing pointer by the starter should line up with the TDC mark on the flywheel.
On Bill's comment, if a valve is stuck open, there would likely be a LOT of clearance between the valve stem and rocker.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.