Just got a '67 Olds Cutlass Supreme 442. Car is an original 442, but engine is not original. It has a '78 403 in it. My trans is a 400 and the rear end is a 10 bolt. Replacing with 12 bolt. I want to put a 400 or a 455 motor in it. I know the 455 is a tight fit & not offered till '70. Car will be for show, won't be drag racing, but want to put the fear of Olds into the late model Chevy and 5.0's running around town. I know there is good and bad with both engines. I have a friend that can build me what I want, but is not an "Olds" person. He is into Chevells. This being my first and only muscle car I want to do it right. Been told 455 needs bigger oil pan to keep from locking up the engine as it pulls all the oil to the top. Told the 400 can not be boared out as the walls are to thin. Either way I have to be carefull about overheating the engine. I know nothing about cars. I like the look of the '67 read up on them, to make sure I was buying a real 442. How to read the codes, numbers and so on. But when it comes to power and best over all engine I don't know. The rear end I have right now has 3.90 gears and hits a wall at 80 mph. The 12 bolt will probably have 3.26. Any and all suggestion are welcome. My friend will understand even if I don't. I want power, but I also want to be able to go on cruses. Like the Power Tour. thaks for helping this newbie out.