There are numerous angle valve engines under RV-4 cowls, but the only one that I can think of referring you to is Dave Anders living at Lake California airpark just south of Redding, California.
Just helped a neighbor remove an IO-360 angle valve from an RV4 to install an 0-320. The previous owner used the 180HP cowling with a few small mods to the scoop and baffling and used a Lexus starter (like mine) from Air Tech. Sam James also makes a cowl you can fit to the RV4 for the angle valve.
