Ahhh...so if the hose clamp allowed the vacuum advance to work a little better, there's a real good chance (like about 100 percent) that you were fighting a vacuum leak as well as a timing problem. They sorta inter-relate, tho.
Now that you have that one corrected, I'd do as was suggested and verify Top Dead Center. Remove the #1 spark plug and turn the motor over manually with your finger over the #1 plug hole. As the piston comes up on the compression stroke, you'll feel the pressure blow by your finger. Now my 292 has low enough compression (last time I chacked this when I installed the HEI) that I could just remove the #1 plug and turn it over with the fan blades. When the pressure stopped blowing by my finger, I knew it was near or at TDC. Then I looked at the timing mark on the balancer...and in my case, it was right on...so my balancer hadn't separated.
When you have TDC, it might not be a bad idea to verify where the distributor rotor's pointing. You can remove the cap and look at the rotor...and if it's pointing fairly close to the #1 plug wire, then you're in the ball park.
Then replace the distributor cap and remove the vacuum advance hose from whatever place is convenient. Plug the end (or fitting) that connects to the manifold, so that you don't induce a vacuum leak. Then set up your timing light and verify that it's in the 10 degrees BTDC area.
Since you mentioned that you have a Pertonix conversion, then you shouldn't have any trouble turning the distributor enough to get the appropriate advance. Then shut it down, replace the vacuum line (remove the plug, too) and it otta run a whole lot better...especially if you didn't forget to put the #1 spark plug back in.
Good luck with it,
