I've researched the vast number of forum recommendations, but can't find any combos similar to mine.

It's a '70 El Camino with a '72 402. Don't know CR, but with the stock 820 heads, I assume it's 8.5-1 or thereabout. Stock except for Edelbrock Performer intake (w/Q-Jet), 1 3/4" headers, and 2 1/2" duals w/H-pipe. TH400, stock converter, 3.08 rear. This is my daily driver and I need good vacuum and idle @ about 800, but just a little lope would be nice. I want to keep the nice, crisp throttle it now has, but still get the most out of it that I can (I know the CR is a limiting factor, but really don't want to swap heads right now.) Suggestions? Thanks!

Get a Lunati 302A1LUN.
It will make your low-CR 402 come alive.
I designed it for the 325 HP 396, and it is more than ample for the 402.
Specs are 254/254 at .0045", 199/199 at .050", .454/.454 valve lift(stock was around .398"!), and 112 LSA, ground 4° advanced.
Vacuum should be around 20" to 22", idle about 550 or less, and it will pull hard from idle.
As a small block grind, the 254 twice won the SCCA Stock National Championship in the Morrison-Cook IROC-Z 305 Camaro, so it has adequate power.
Headers are nice, if that's in your plans. It will work with 2.56 rear gears, on up. It also uses stock converters and stock springs, although if the springs are old, I'd replace them. You obviously also need new hydraulic lifters.
If you can afford to wait for a month or so, you might want one of the new VooDoo cams, which will be available in cam & lifter kits from Jeg's and Summit, etc.
The 60200LK is 250/256 at .008", 207/213 at .050", .466"/.483" valve lift, and 112 LSA, also ground 4° advanced. This is as large as I would run in an engine such as yours.....

UDHarold

Thanks a lot Harold. I can definitely wait. I'll keep an eye out for the Voodoo cam.