I'd think about a lockup 904 out of a TBI truck (so you can defeat OD with a flip of a switch) a loose converter (something that stalls ~2800RPM, flashes to 3200) and 2.76's...might be less work than the tunnel mods for an A500...

or switch to a stick and use an iron case A833OD...

the HP loss with the 318 manifolds will be larger than the article, due to the PUNY nature of the 300HP motor's cam.

personally, I'd ditch that crane cam for a comp XE265HR, and add headers...

and the engine doesn't look stock with magnum VC's...I'm using LA VC's with good LA VC gaskets...

1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)