This was on my 914-6 conversion when I bought it. I don't know if it'll work with stock 914-6 heater boxes. It came out where the engine mates to the tranny and used an early LONG 911 soft oil line. It worked perfectly, I just converted everything to stock 914-6 parts.

$65 shipped in the lower ConUS, I'll even toss in the larger fitting that screws into the block.

Here's how it routed, pretty slick as he used 993 heater boxes. It'd probably work fine with headers, don't know about 914-6 heater boxes though.