With your cam, the 272° is total duration. You can have an "aggressive" cam that opens up quickly (aka steep ramp) or a gentler one that opens more slowly. Yet both have the same "advertised duration".
Information you need about the cam is generally:
Total duration (Advertised duration)
Duration at 50 thou
Max lift (preferably of cam lobes, not valve lift)
Intake lift at TDC (lift at TDC)
Centreline or angles at opening / closing
Operating (power) range
Recommended idle RPM (which may note if a stall converter is required)
Clifford should be able to get that information to you. If not, there's more than one way to skin a cat.
Jumping back a step, the reason I mentioned your ignition and electricals is due to experiences with these issues. Sometimes, a rebuilt unit can be way off what you need. It may be assembled wrong, or have wrong components. That was my concern with the distributor.
As to alternators - I have seen them work fine at low engine speeds, then with warming up and increased load, the output degenerates and the motor coughs, splutter erratically and fouls plugs (leading people to say the carb is running rich!
). Proper testing procedures on each of these is the only way to be sure (unless you're experienced in either field). Lifetime warranties are well and good, but a diagnosis is sometimes worth more.
Adam.
Information you need about the cam is generally:
Total duration (Advertised duration)
Duration at 50 thou
Max lift (preferably of cam lobes, not valve lift)
Intake lift at TDC (lift at TDC)
Centreline or angles at opening / closing
Operating (power) range
Recommended idle RPM (which may note if a stall converter is required)
Clifford should be able to get that information to you. If not, there's more than one way to skin a cat.
Jumping back a step, the reason I mentioned your ignition and electricals is due to experiences with these issues. Sometimes, a rebuilt unit can be way off what you need. It may be assembled wrong, or have wrong components. That was my concern with the distributor.
As to alternators - I have seen them work fine at low engine speeds, then with warming up and increased load, the output degenerates and the motor coughs, splutter erratically and fouls plugs (leading people to say the carb is running rich!
). Proper testing procedures on each of these is the only way to be sure (unless you're experienced in either field). Lifetime warranties are well and good, but a diagnosis is sometimes worth more.Adam.
#1-new engine, 200 miles, not even fully broke in yet. #2- It ran good after rebuild but after modified head went on problems came up. That tells me the shortblock is fine,the cam,lifters and chain would all be ok. Rhodes lifters bleed down oil pressure at idle making that cam almost stock if adjusted correctly with good oil pressure. #3- Did you put the weber on after the head swap or before? If you are using an adapter for the weber this helps alot because you probably have a box with the old carb in the garage that you know idles well that you can bolt back on for a test. Here are a couple of things I'm thinking, you changed distributors but you hooked up to a full time vacuum source, try a ported one. That will help with the confusion on timing. Get new base gaskets for your old carb and reinstall. Dont worry about linkage and all that, we need it to idle first. plug off all vacuum connections from the carb for now. fire it up, if it runs good at idle after warming up and some tuning your carb needs help or you have problems in the vacuum system. If you still have problems after that I would say you have something wrong in the head : 
yes I mean the head on the car like too tight of valveguides or misadjusted rockers/valves that aren't closing all the way. My guess is it will turn out the carb in the end, go back to basics and work from when you first developed your problems. One time working all weekend long trying to get #1 on tdc and getting the distributor set correctly on a ford 2.3 after the timing belt snapped and second and third guessing myself standing in front of a popping/coughing car just worn out my wife came out , looked at the engine and said" what are those marks on those gears for? 20 minutes later it was running. Good luck
) I just re-read this thread.
The Rhodes lifters act to effectively REDUCE the duration/overlap of the cam. This allows a relatively 'hot' cam to have better idle and low speed characteristics and still give good high speed performance. Now that the Rhodes lifters are apparently gone, you have a pretty big cam that isn't getting the help from the Rhodes that it used to. This is what is requiring it to need so much ignition advance in order to idle. Trouble is, it is too much at higher speeds and pings as you have noted. The distributor advance curve needs to be altered (limited) to allow it to perform at both idle and high speed. Don't panic just yet, this isn't difficult to. The first thing I would do is to mark the crank pulley in Five degree increments up to at least 40 degrees. You can put some white adhesive tape around the pulley, and calculate from the circumference of the pulley how far apart the 5 degree marks need to be. Carefully mark these increments, then you can rev up the engine while checking with the timing light to see how far it advances. The initial advance will probably need to be around 20 degrees, and the full mechanical advance probably won't be happy much over 35 degrees (KEEP THAT VACUUM ADVANCE UNHOOKED FOR NOW!) Get it tuned to where it will idle, then you can move on to higher speeds. I can give you a more detailed description of installing the distributor if you need.
