The only bushing I can imagine holding up without pressure fed oiling are the Isky Speedway redzones...... but you should talk to them about it and be sure to tell them the lifters won’t have any oil feed to the bushings.

You might consider a little milder intake lobe as well, with a little less lift.
Just let the boost do the job.

A 273@.050 lobe that’s .521 lift has some pretty fast action.

If it’s a Comp, I’d be curious to know the lobe numbers on that cam.

I also agree with Todd about stepping up to a larger cam core if what you have is still using a std cam core.

You would really be helping out the lifter pressure angle situation, especially with that much lobe lift, by increasing both the cam core diameter and the lifter diameter(and the accompanying bigger wheel).

Obviously it’s easy to sit at the keyboard and “armchair quarterback” the situation after the damage is done...... but IMO, your exact combo........ very high lift lobe, high pressure angle, high open spring load, Sportsman lifters, no pressurized oil to lifters........ that’s a recipe for failure.