depends on the engine you could get one to run horizontal if you really wanted. you will probably need to make the bottom sump deeper and flat to the ground along with the pickup moved. look where the oil would run to the side of the head if its not draining would need to fit an external oil drain. and then if your using carbs modify the inlet so they sit how they sat before
Hi, It's fairly common practice on coaches with underfloor mid engines laying flat and they are usually dry sumped. You really need to avoid the crankshaft hitting the oil because it puts too much shock loading on it.