I always thought cam bearing number 4 supplied the oil to the valve train. Regardless, cam bearing number 5 needs to be aligned properly. Also, there should be a plug in photo number 1 above below the "M" and a second plug in the "tube" pointed towards the ground in the same photo.
I have to agree here with Chryco Psycho. I've been tuning my 70 Challenger for years with nothing but a vacuum gauge and Sears tachometer! Vacuum gauge for carburator tuning and RPM for timing! That's the way my dad taught me many years ago!
Is the choke working properly and opening up after warm up? Which carb are you running? Electric choke? Manual choke? Stock choke heated by intake? I'd make sure the choke is working properly. Are you running stock exhaust with the temperature controlled valve on the passenger side? Is it...
If sticking with the big block HP exhaust manifolds use 3" diameter pipe from the manifolds to about mid-transmission (5 to 6 feet long). Install your cutouts and then reduce to 2.5" pipes to the mufflers. Unfortunately Flow masters are made in China these days. 🙁 Any turbo type muffler will work.
You just need some better exhaust gaskets (copper or remflex) or machine the headers flat so they fit tight against the cylinder heads. From the factory Mopar used NO exhaust gaskets on big blocks.
Two cylinder heads deserve two exhaust pipes! 318 engines do very well to modifications like dual exhaust and a four barrel carb! And the stock 340/360hp cam does well in the stock 318!
The Borgerson adapter needs welding, but Peter at Bergman Auto craft sells an adaptor you need! (Link might not be exact.)
https://bergmanautocraft.com/product/borgeson-steering-box-small-sector/