Rob;
Good question. The OE PV specs on the 4053 (and 4346) carbs flies in the face of "conventional wisdom" that states you should run a PV that's rated at 1/2 of what engine idle vacuum is. Since most 302's idle around 9-11", that would call for a 4.5 to 5.5 PV. However...stick a 4.5 PPV in a 4053 on a basically stock 302 and watch a mysterious off-idle hesitation appear...been down that road previously with numerous customers who tried it themselves.
For consideration: The only differences between a 4053 and a 4346 carb are the vented pri. bowl and an 8.5 PPV on the 4346 instead of the non-vented front bowl and 6.5 PPV used on the 4053.
I would be interested to know what your L72 idle vacuum is, and what PV you're running up front (blocked rear, correct?).
Keith;
I've found that on a stock 302 with manifolds, a 70 primary jet seems to be enough to eliminate the lean cruise issue, and 72's are well-documented for best performance. Any time I build a carb for a 302/L72/L78 with headers, it automatically gets 72's in the front.