One tooth of timing is way too much either way.. My guess is it one tooth off retarded.  Make sure the timing marks are lined up so your cam is in the straight up position.. There are no adjustable cam components for these engines..  Is the cam reground stock? 
If your  timing marks on the damper are off due to the damper ring slipping, you will get an erroneous ignition timing reading. Try advancing the distributor while it is running.  If the engine smooths out, give the engine what it wants not what the timing marks say. One more thing to check  You may have a big vacuum leak somewhere which would make it hard to start and run hot due to lean fuel mixture.
 Do you have hydraulic or solid lifters?  If hydraulic, the rocker arm adjuster screws may have too much pre-load on the lifter and it is not letting the valves fully seat.. Just another item to check..

I got an engine to run once being a tooth off and it was unbelievably bad. Back when it first started building performance engines I had to get a wider key and machine the sides to get an advance or retard; there were no notched crank gears or buttons for cams. and it was a pain. Thanks to my dads mill and his advice i was able to do it; then remember with no chain put it in backwards. I also does not sound right that a cam grinder would grind that much into any cam and only on a new casting or billet. Interesting reading and suggestions for sure... 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

OK, Timing: we have gone through the gambit of rotating the distributor and have found the "sweet spot" where it runs and idles OK. It is not a stock grind, a little more lift and duration went into it from a very reputable shop, not super aggressive. We put in longer pushrods to accommodate the cam. We're pretty sure the issue is here but are still working on it.  Timing marks on the damper may be an issue with the new cam but our issue is bad compression numbers on all cylinders and hard starting.   It's got to be in the valves.  We did our own seating and grinding so we might end up swallowing our pride and taking them to a real shop for verification of our work. We could also end up going back to the stock grind, I have an extra cam. Funny, once we get this thing dialed in we're gonna take the top off and set up our webers and then back to the drawing board with linkage and fuel lines.. Trying to find a generic throttle linkage kit for the four twin stack webers has been impossible. 
RB: hydraulic lifters, vacuum checks out at 20-21 with just a very little flutter.

Did you check your rocker arm ratio and valve tip relationship?  With more lift, your longer pushrods may be bottoming out in those hydraulic lifters and holding the valves open a little when everything gets hot or heat soaked, losing compression.  I would think the stock pushrod would be more appropriate with more camshaft, not longer ones.  Joe-JDC

JDC

Good thought Joe, that's on our list. Fortunately there is a lot of play in the stock rocker arm adjustment.  Maybe this engine wasn't meant to have a more aggressive grind.

20-21 inches of vacuum is a lot..  That cam must not be a big step up from stock..  It seems that compression now is your main issue.  I would start to maybe question your valve job.  I know my attempts at home brew valve jobs have not had great results.. Before you pull the heads i would invest 40 bucks in a leak down tester and zero in on were the compression leakage is happening..

Nothing in the inherent design of the Lincoln Y block would prevent use of a hotter cam... As long as you account for valve clearance at max lift with the block and pistons..   I have Lincolns where I run over .600 lift and 250 duration.. But accommodations have to be made for valve clearances..I doubt too aggressive of a cam is your problem

To piggy back on Joe's comments  one thing you could try is to back off all the adjuster screws 1 or 2 turns and see what happens.. That would assure the hydraulic lifters are not bottoming out and holding the valves off the seat

All comments up to this point are valid.  I’ll add a couple more.
 
That slow turnover of the starter can be a result of a dragging starter.  Worn bushings in the starter can contribute to that.  Performing an amp load on the starter while turning over the engine could help to clarify that.
 
If the compression tester is old or has been used on a hot engine, it can be giving erroneous readings.  When getting abnormally low compression test readings, performing an accuracy check on the tester would provide some additional confidence in the readings.

Lorena, Texas (South of Waco)

Leak down test coming this week. You're right, the cam is not too aggressive.  Gotta be dem damn valves.

Well...It's not the valves.  It's the cam shaft. The new grind is so far off that it's affecting everything.  There's only one cam shaft shop in the whole county so we're back to ground zero.  Ted, if you know of a shop that can repair our CS, please let me know.  Jeff has been checking around and we're not the only ones that are not happy.  Rosen down in Cali is backed up over a month due to covid.  In the mean time, we took the heads to a local  old timer that's going to put hardened seats in them.  Once we get a good cam shaft, I'm sure we'll be ready to go.