You know how it is. Cold in the barn where you store your prized possession. There's work you should be doing on your car but decide to stay in the house where it's warm. Your mind starts to wonder and your thinking of putting a bigger engine in the car. Have been looking for a 360LA with a 727 trans. out of a car, and in Northern Ohio there's not too much to choose from. Here is the question: what is the difference between a 360LA and 3.9 Magnum. Are all the bolt patterns the same ie: head bolt, exhaust manifolds, flywheel (converter) housing, engine mounts, crankshaft bolt pattern, timing cover, distributor bore and any others I can't think of now. Are the physical dimensions the same. I've rebuilt the 273 that's in the car now and have put only about 50 miles on the car since rebuild before winter. May be happy with what I have but Tim The Tool Man and I are on the same page (MORE POWER).