Used car factory part 3- Interchangeability

It appears I opened a can of worms with the last couple posts. I encouraged people to ask questions and I've had a few good ones. Here's the answer to some for everyone's benefit. #1 Engine / Transmission Compatibility. GM guys have a huge advantage here. A Turbo 350 is the exact same size as a Powerglide / Super Turbine 300. The trans mount and the driveshaft yoke is the same. This means swapping the crappy two-speed 'Glide for the excellent 3-speed Turbo 350 is literally a bolt-in. Also, Turbo 350's are incredibly tough in stock or modified trim. They will stand up to any small-block and all but the most radical big-blocks. This saves the engine-swapper a substantial amount of time and money as he doesn't have to change the transmission, crossmember, or shorten or lengthen the driveshaft. A Turbo 400 is virtually indestructible which is why they are used in drag racing to this day. A short-shaft 400 will bolt-in where a 350 was if you desire, but you'll have to change the driveshaft yoke. Further making it easier for GM guys is the bellhousing bolt-pattern. Chevys are by themselves, but Buick,Olds and Pontiac share the same bolt pattern. This means if you had a 403 Olds Trans-Am and wanted to swap in a 455 Pontiac, you wouldn't have to change the tranny-you could use the one already in the car.  Fords and Mopars are not so co-operative. The 289/302 share the same bellhousing bolt pattern, but a 351C is different. This means if you wanted to swap a 351C into your Mustang that originally had a 302, you'd have to get a different tranny. The 351C / 400C / 351 /400M share the same bellhousing pattern as a 429 / 460, but their different from a 352 / 390 / 428. Mopars aren't quite as bad, as the 727 Torqueflite was used behind 340s and 360s as well as the "B" and "RB" engines, but if you have a 318 car that you want to put a 440 in, it's not just a matter of strength, the 904 trans won't bolt up. Not like the Chevy guy who can yank his 350 for a 454 and bolt it right up to the TH350. Sticks are an even bigger nightmare for Ford guys. GM used Saginaw, Muncie, and Borg-Warner 4-speeds over the years, and they all will work behind most Chevy, Pontiac, or Olds engines, depending on whether you have a 10-spline or 26 spline clutch. But buying a different clutch disc is nothing. And most GM cars use the same rear trans mount and crossmember style. Fords are different. Crossmembers and tranny mounts are different for most cars. Mopars are only slightly better. The three or four-speed stick behind a 318 won't hold up behind a 440 or a Hemi. Since the 340 was a high-performance package, they usually have the 833-i.e.-big-block tranny anyway, so that makes swapping easier, but do you really want to Modify an original 340 / 4-speed car?  # 2 Bracket and accessory interchangeability.  Again, GM guys have it easy. Pontiacs are externally identical from a 326 to a 455. Ditto for Olds engines from a 330-455. This means stuff like alternator brackets, Power steering brackets, A/C compressor brackets, fuel pumps, water pumps, oil pans, valve covers, etc all interchange. Small-block Chevys are the same from 1955-86, and from 86-99. Big-blocks are the same from 1965-1990, and from 1991-up. That makes your life a lot easier because your not chasing a thousand different parts to make it run once it's in the car. Not so with Fords. If you swap a 289 for a 351C everything is different. If you swap a 390 for a 460 everything is different. Worse yet, unlike taking a 350 out of an Impala and just dropping it in a Camaro, if you take a 351C out of an LTD and want to drop it in a Mustang, the brackets, water pump, and oil pan are all chassis-specific. In other words, if you don't have Mustang-specific accessorires, your in trouble.  Mopars are like Chevys in this respect. You can swap a 340 or 360 for a 318 easily, and a 440 will bolt in place of a 383 and you might not even have to change the hoses. However, going small-block to big-block means big changes-again brackets, tin, accessories are all different.  I'm not trying to discourage anyone from building their dream car, but I want you to be aware of some of the problems you may encounter that you might not have thought of. Mastermind