Loss of power with new cam
If you lined up dot to dot and piston #1 at TDC you are not on the compression stroke. Rotate crank one complete turn and you will be on the compression stroke, I believe your timing marks will be at 12 and 12. You could also just find out where your dizzy is pointing on the compression stroke and make that your #1 plug wire and follow the firing order for slant six.
I was talking relative to the engine. Not the world around us:) If he lined it up dot dot and dropped in the dizzy and made that his #1 it's wrong. Just trying to help the guy out. Those instructions are for a Chevy.
These answers are confusing the issue. Dot to dot, 12/12 have no meaning if the engine RUNS. (That is, the distributor is installed on the compression stroke, and it won't run any other way) So long as the cam drive marks are PROPERLY aligned, one or the other, this is the best you'll do if you haven't or cannot degree the cam. The only meaning this comment has is if the engine will not run, IE is blowing flame out the carb and won't run.
Here's how I see this:
VALVE ADJUSTMENT: How did you accomplish this? How did you rotate the engine? I use what is known as EOIC, which means
You rotate the engine until an EXHAUST valve just starts to OPEN, and you set the intake on that cylinder.
Then you rotate until the INTAKE has opened, and is approaching CLOSED, and set that exhaust valve.
Use the proper feeler, and one .001" or .002" larger for a "go/ no go"
TIMING: Generally, all factory distributors in engines made after 66--68 have crappy "smog" advance curves. You need to SERIOUSLY consider having the dist. recurved or replace it with a performance dist. which has a short curve.
It is also possible, of course, that the dist. has something wrong, IE sticking advance, etc, worn bushings, which enter the picture
You want LOTS of initial timing, much more than factory. You can start with a vacuum gauge, time it for a "peak" in vacuum. Reset idle and mixture (engine up to temp) and recheck timing/ vacuum. You REALLY need to figure out a way to check total mechanical advance, as well as mechanical + vacuum. This is harder on a /6 because of the thin dampener.
Also, how sure are you that your timing marks are accurate? A piston stop is the usual way to check on an assembled engine.
FUEL. It may be possible, here again especially in the case of a "smog" engine, that your carb is now on the ragged end of "lean." In any case, a performance situation, IE hotter cam, exhaust, etc, changes the carb situation.
And of course as others have leaned towards, just how sure ARE you that the cam is actually lined up properly. And here's two other wrenches in the gear works, in this case, sprockets.
1--Some cams are ground advanced or retarded by the cam grinder. I've never figured this out, because if you are not aware, and have not degreed the thing, this alone can cause problems.
2--Some engines (don't know if /6 is one, Ferd did) had later model "smog" cam drives off center by the factory. This is especially a problem if you have a cam like (1) above, the damn thing could be as much as 8* off!!! just from the cam drive and "off ground" cam. I don't have a definite answer on this, I would certainly look into it.