Compression Ratio, Will I be able to tell the difference? Options

[sdoolin]

Rebuilding(ish) my 2056. On my first build I was able to achieve a compression ratio of very nearly 9.0:1. With this build, I am having to add .020 spacers below the jugs to get any measurable deck height in the jugs. I am calculating a compression ratio of 8.6:1.

Will I notice the loss in compression ratio?

[sdoolin]

I'll likely button this engine up this weekend, and I'm looking for suggestions on how to verify oil pressure, before I install it back into the chassis. I am considering:

1) Adding oil and turning the engine by hand (no spark plugs) until I see oil at the oil filter mounting point just upstream of the oil pump. This seems like it'd be difficult at best (turning against the friction of the rings and all of the valve train), and maybe even impossible to really generate any oil pressure.

2) bolting on the transmission and using the starter to turn the engine until I see oil at the oil filter mounting point.

I am very nervous about oil pressure as the only reason I'm doing this project is because I ran the engine (briefly) with low/no oil pressure and seized the rear most crank bearing. I never did determine with any confidence why there was low/no oil pressure. I suspect one or two things, but am mostly unsure.

All actionable suggestions appreciated.