I am currently working on a '64 Ranchero which originally came equipped with a 170 cid 6cyl engine & Fordomatic trans. The engine was in trouble so I purchased a complete used engine which I believe to be a 200 cid. Correct me if I am wrong. Number on the block reads C6DE-6015-B. I had the Fordomatic 2-speed automatic trans completely rebuilt and want to use it behind the 200 which currently has a flywheel bolted to it since it was mated to a manual transmission. My question is after removing the flywheel can I simply transfer everything from the 170 to the 200 and bolt up the Fordomatic? By "everything" I guess that would mean just the plate that goes between the block and trans. Is there any reason to remove the pilot bushing in the 200? Thanks in advance for your input. The wife is really after me to get going on this or one day I will come home and "it will be gone".

um, you will have a bit of trouble with this combination.

The 200's part number (C6) indicates it's from 1966. That was the first year that for the more modern 6-bolt bellhousing pattern. Up to 1965, the 170 and 200 engines used a 5-bolt bellhousing pattern.

Therefore, your Fordomatic's transmission will not bolt-up. However, it should not be difficult to find a 1966 or later automatic transmission that will bolt-up. The 6-bolt pattern was used for the 6 cyl and small-block V8's into the 1990's. Given your car probalbly has a really short rear axle gear, (like a 4.10:1), try an early '80's 4-speed automatic, like a Ford AOD. This will give you MUCH better highway cruising ability, with better gas mileage, to boot. An AOD or any 3-speed auto will give faster acceleration than the slow, 2-speed Fordomatic.

The alternative is you might find an adapter to get the Fordomatic to bolt up. I am not sure if they ever were built, but it may be worth looking. (try transdapt.com)

The 1966 200 engine received some upgrades that make it better than the 1965 and earlier 200 and 170 engines, so you will get some benefit in using it.

I am not sure about using the 170 flexplate in the engine. It depends on if the 170 and 200 were internally balanced, or externally balanced.
If both engines were internally balanced, you can swap them. But if one or both were external, then the flexplate is not interchangeable.
Possibly a local engine-building shop could tel you.

Finally, ideally the pilot bushing should come out. But if it's really jammed in there, just leave it.

Oh, yeah, tell your wife the Falcon-based Rancheros are REALLY valuable. By living in CA, she has a distorted, unrealistic view of old cars. All of us poor souls slaving away in the Rust Belt have not seen cars like these in 40 years. :)

Thanks very much for taking the time to respond to my inquiry. Since I have too many irons in the fire at this time, looks like this may be one of those "restoration started but no time to complete" sales. I do, however, have a completely rebuilt 170 head and the rebuilt trans. My quickest and least expensive way out is to find a decent 170 block. We will see. Thanks again!

What's wrong with the 170?

When I purchased the car several years ago, the head had been removed and it looked as if water had gotten into the oil. I found a rebuilt head at one of the swap meets for $80 so I purchased that since I wanted to start with a semi-fresh engine. I still have the block but it has been exposed to the elements and I saw some water sitting on top of the pistons after our recent storm. My plastic sheeting must not have held up. Maybe that block is salvageable. I'm just not sure. The '66 200 engine was another good deal but I should have researched it's application more before purchase. I could also go the manual transmission route. So many choices with so little time (and money!). Craig

I see your point. Either way, it's going to be a bit of time and money. But, imo that's no big deal. I have had projects lying around for years before I had the time to get to them. :)
It's no fun if you feel that you are being rushed.