If your lifters went bad, you almost certainly need a new cam. Usually the two go out together, but I guess that's not guaranteed. I wouldn't want to gamble on needed to redo the job again 10K miles from onw with a new cam, new lifters again.

The IPD/Isky/SBC lifters have worked well for me, when I rebuilt my bottom end I got a set for an 'Iron Duke' (half of a SBC) for a very nice price from Isky, the pushrods from them, and an Isky cam.

Still not entirely sure you've nailed the excessive blow-by issue or not - generally cam lobe failure make the engine run horribly (when they've gotten to the almost flat stage where the valve doesn't really open any more) but the air just doesn't flow through the cylinder, it doesn't get re-routed into the block. Even if it's the exhaust valve that doesn't open, there shouldn't be much more blow-by than normal - it's just like continual 'compression' strokes, it doesn't really draw much more air into the cylinder on each intake stroke since it's still full from the last (although you can get lots of backfires if it did fire and there's hot gasses in it that try to go back into the carbs). And a flat intake lobe just sort of shuts off that cylinder.

Excessive blow by is usually either rings that aren't sealing, or holes in the piston. Or very rarely holes in the block, but the rings is by far the most common issue.
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'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)