how does a 318 engine run if timing is off ?

Classic sign of fuel-tank not being vented, and/or, the hard line sucking air.
it's a wonder your engine runs at all with those short-reach lawnmower plugs in it;
LA plugs have always been 3/4" reach, which in the Champion line, carries the prefix "N".
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As for cam-timing, in a 318LA with a stock cam, she actually runs pretty good with an out-of-time cam.... as long as the ignition timing is reasonably close to correct.
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As for your 268/280/110 cam (224/230@050), that's a good cam if your engine has the compression for it. This cam has a generous amount of overlap, and if you exploit it, she will return good torque AND power over the nose; and reasonable fuel economy.
But, if the cam gets too far from an ~108 installed center line; retarded it will give up cylinder pressure and advanced it will give up fuel economy. But it will still run just fine, until it gets to be about one tooth out on the top sprocket. But, that alone is NOT you problem, as others have said.
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Twenty years ago, I ran a cam nearly identical to yours, in my 367, and it has always been my favorite. I drove it the track once, 3 hours away. She ran [email protected] on 245 street tires with 3.55s, and that was good enough for me. I watched the big dogs for a while, then drove home.
Of all the cams I have had in this 367, it got the best fuel-mileage too, allbeit geared for 65=1600 in overdrive, lol. I toured that combo everywhere.
Sadly, that cam died.