When it comes to 68-72 Chevelle wipers typically only the stripper model / post / 300 deluxe cars had the non-recessed park wipers that parked up on the windshield when off, nearly everything else had the hideaway / recessed park wipers. I think I've seen less than 10 68-72 Chevelles in person with non-recessed wipers over the last 25 years or so.
The recessed park wipers also used a different driver's side wiper arm with double links and the transmission linkage inside the cowl is a bit different than a non-recessed park wiper car.
IMO a 68-72 Chevelle looks a bit goofy with non-recessed park wipers since they stick out above the hood line sitting up on the glass even when they're off. As far as I know there's no longer any updated / late model style aftermarket motor kits for Chevelles out there offering recessed park. That means you're stuck with using one of the large and rather ugly original or reproduction original style wiper motors if you want recessed park. DSE stopped offering their recessed park late model style motor for Chevelles many years ago (I heard it was for reliability reasons-- lots of failures, and now they can't even service or repair the recessed park kits they sold years ago so if you have one and it dies you're SOL.)
If you want to keep recessed park, you may be able to relocate a stock recessed park wiper motor over to the far left side of the cowl under the driver's side fender and build some extended linkage for it, but I'm not 100% sure it will work... never tried it myself.
If you keep the OEM recessed park motor but want intermittent / delay, if you search over on chevelles.com there's info how to make an adjustable delay circuit and switch that works with the OEM recessed park motor and doesn't try to park the wipers every time it does an intermittent pause... better than the off/low/high which is all you have to choose from with the factory switch.
https://www.chevelles.com/threads/ad...part-1.526153/
As far as the valve cover breather, what I've done on another car for cleanliness was locate the bungs and hose connection at the rear of the valve covers to be closer to the catch can but welded internal baffles/tubes that extended to the center of the valve covers, that way they're picking up crankcase vapors from the center of the valve cover and not likely to get covered by oil under either hard braking or hard acceleration. However, that was on an SBC with shaft rockers and tall valve covers that had enough clearance for the long baffle. LS valve covers sit very low and close to the rockers and there probably wouldn't be enough room to do that. If you have a vertical baffle out of the fill cap with enough height to it, it will probably work OK and not push oil into the catch can at WOT.
I'd say try what you have now, but check the catch can after a couple of WOT pulls and see if it's pushing excessive oil. You don't want to fill the can up and have it drip down on the exhaust manifolds.