There are a bunch of SBC 2.100 journal rods from 6.00-6.125-6.20-6.250-6.30

Just about anything to fit what you need.

The crank would be chevy 2.1" rod journals so the next size down would be a 6.00" chevy rod. That would result in a piston with a compression height of 1.705" assuming a 9.6" deck height. Would the oil ring still be in the pin area?

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You can still use a 6.125 chevy rod and that would should
clear the pin hole

well, IF you use a 6.25" rod, assuming 9.6" deck height, that gives a 1.455" compression height, which is .002" shorter than the compression height on most diamond brand pistons for a 4" stroke/6.123-6.125" rod, so that gives you some off the shelf piston options.

as far as side loading, do the math. if you use a 6" rod, at 90 degrees from TDC or BDC, the rod is at a 18.4 degree angle from vertical. so 31.6% of the downward push is side loading. with a 5.7" rod, that increases to 19.4 degrees and 33.2%, with a 6.25" rod, it decreases to 33.3% at a 17.6 degree angle...that may not be where max side loading is at, since the downward force maximizes much earlier than 90 degrees after TDC....

You are worrying about nothing.

Chevy pistons for a 6" rod 350 have a compression height of 1.25 or 1.26. The oil ring is safely above the wristpin in those. Consider the 5.7 Hemi engine. Its stock compression height is around 1.25. Chevy LS motors have a CH of 1.31 - 1.34. These are engines that have to meet emissions for 100K miles. If you check it out almost every engine designed in the last 10 years has a compression height of 1.4 or less.

I'd say almost what was said above, pick a stroke and block, pick a rod you want to use and get a piston to match. For example, I might see some Oliver 6.350 chevy rods on the 'bay. So for my 9.60" block I'd pick the 6.350 rods, a 4" crank and 1.25" shelf chevy pistons.

R.

so it looks like general consensus is that the shorter pistons will be fine, and that the dwell theory really seems to be kinda moot in the grand scheme of things?