Timing set. Bingo!

The Y-blocks have a fosdick way of lining up the crank and cam sprocket. Did you use a Motor Manual or other manual to put it back together and are you sure you got the sprockets in the correct position? Here are instructions written by Larry Kennedy.

First step in installing the timing chain and gears is to check the spacer ring; be sure the chamfer side is toward the cam. Next, install the woodruff keys in the crank and cam. Now slide the crank gear on the crank and position the timing mark by turning the crank, to the 3:00 o'clock position. Install the cam gear and position the timing mark on it at 3:00 o'clock. Now remove both gears. Place both gears in the timing chain with the timing marks 12 pins apart. Start the crank gear on the crank. As you slide the crank gear down, start the cam gear over the cam. Line up and engage the cam gear keyway with the key on the cam first. This will slow you to turn the cam so you can engage the key in the keyway on the crank. When both gears are installed, count the pins between the timing marks. There has to be 12 pins between them. Last step is to install the fuel pump eccentric and hardware. Torque the cam bolt to 35 ft.-lbs. You did use Loc-Tite on that bolt, didn't you?

Here's a link to the entire piece on the rebuild:
http://members.aol.com/yblock/258hpyblock.htm