Slant 6 to 340 Engine Swap in 69' Dart

I did this swap and my wiring harness worked fine..as stated shorten some of the wires.
i made my own conversion mounts...just copied trans dapt.
bigger torsion bars and I would upgrade to discs before i did anything else.. Manual steering is easy on an A body and gets the junk out of the engine bay.Just don't crank in the parking lot until you're moving.
bigger rad..read Griffen exact fit and you can idle in heat without worry.Keep your cam size modest if it's a street machine.Same with your rear tire size.This lets you use a stock converter. Too many guys put a bigger cam in and are disappointed.904 is fine and saves weight and less parasitic losses.
Now read Rusty's guide to hot rod bliss..save a bunch of money and avoid the flavours of the month and have fun.
Good Luck!