As miker brings up, 0.019” hot valve lash is a good place to start without doing some serious mapping of the lobe profile.  Some of the older cam grinds tend to like a lash in the 0.022-0.025” range but many of the new grinds prefer a lash that's tighter than the stock 0.019”.
 
If the manifold vacuum is low at idle, then increase the lash ~0.004-0.005” and note how much the manifold vacuum at idle increases.  This will also help the idling characteristics and especially if the engine currently has an idle considered to be too rough or must idle too high in which to continue running.  If the engine tends to have a flat spot or hesitates right off of idle, then increasing the lash will also help with this without digging deeper into the carburetor in which to correct.

Lorena, Texas (South of Waco)

Slumlords correct, but if you can't get more info you're going to have to start somewhere. I know you're having some tuning problems, but you just going to have to be methodical and eliminate one at a time. I think a vacumn gauge is going to be your best bet. Not only to help with the mixture adjustments, but also the timing. Once you get the motor smoothed out, seeing what the idle vacumn is will tell you a lot about the cam. A "not quite 3/4 cam" doesn't say much, but it could just be its the E or F code grind. I've run the 300 Isky, and Mummert's 280 series and they tuned pretty much like stock, and made 15" or better at idle.

I'd start with the stock valve setting, hot, and see how it sounds. Hopefully, someone like Ted will chime in with a range of adjustments. He's seen more cams than most of us put together.

Once you get past the different sound in the firing order, an experienced engine guy will be able to make a rough guess on the cam. In the past, without this huge database on the Internet, we all pretty much figured it out from scatch. You will too.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

The problem is that non stock cam may require a different valve setting. Intake and exhaust could also be different. Any possibility of contacting the previous owner to get the spec's?

I just found out after owning my car 8 years that the person I bought it from put an over sized cam in, said it wasn't quite a 3/4 cam but bigger than stock. What if anything has to be taken into consideration when tunining the engine if anything?