250 to 200 swap

[Anonymous]

I am going to have to do a swap from my 250 to a 200 because my 250 has a main bering going bad. The 200 is out of a 1980 ford mustang. What will I have to change, will the intake need to be changed or will the stock carb from the 250 work?

Thanks in advance

 

[61Futura]

The bellhousing won't bolt onto a 200. You may have to move the fan closer to the radiator. Oh yah, I think the water pump and radiator of a 250 uses a larger diameter hose, so you'll need a new radiator. The motor mounts are different. If you change the carb, you should make sure the distributor vacuum advance matches the carb port. I think the 2 engines use a different length oil pump drive shaft on the distributor. Keep that in mind if you want to reuse the 250 carb & distributor. I'd stick with a 250 unless I had a donor car to get all the different parts needed.

DISCLAIMER I have never attempted the swap, I've just researched doing the opposite swap. I have a 250 I can't use. I've pulled the C9 head off of it. Looks good but some of the valve guides feel worn.

 

[Anonymous]

I was fearing that I would have to change a lot. The 200 has motor mounts on it already, but I don't think they will work because the engine came out of a mustang. All I really need is a 250 block, because the head is fine. If it wasnt for the main, then the car would be fine. Its runs like a champ unless I am going down the road at about 50 then it tends to have a knock. Tell ya the truth I would rather keep the same engine so I wouldn't have to change anything. Besides that, the 250 has a godawful amount of torque in comparason to a 200. If you know where I could get a good block or if you can find a way to ship yours if you want to sell it let me know because I am going to have to do something here pretty quick because of the fact that I don't want a car that I cant drive and drive.

Thanks

 

[61Futura]

It's too bad we are so far apart. I don't know how I'd crate & ship a 250 short block to you. I'd just like to get it out of the garage. I was told it came from a "69 Mustang and only had 500 miles on a rebuild before is was replaced with a V8. I thought some valves seemed a little loose in the guides for having such low mileage. Maybe they didn't redo the head. I've got a 200 on my engine stand that I may rebuild to replace my 170. I was planning on using the C9-M head, but don't want to spend $300+ on rebuilding another head unless I get headers to make the larger intake a noticeable improvement. My 170 has a newly rebuilt head. Currently, I've decided to try and find a whole donor car with a 200 so I get a new tranny to get rid of the 2 spd auto at the same time.

 

[Anonymous]

A knock? Don't trash the whole motor! New bearing set, oil pan gasket, oil.... 'bout and 5hrs of work?

Worse case scenario, pull the engine and install a new crank ($140...). A lot less worse than a 200 swap and keep the power.

 

[Anonymous]

I would hate to lose the power. It does seem to be jumping time or something. I was driving it up the street to the store (so yeah its not that bad I hope) and the thing starting missing and backfiring when I had it about half throttle. When i let off it was fine. Then I get it home and shut it off, try to start it again and it is very hard to start but does start. I wait about 10 mins and she starts right up like always. I think she needs some attention.

 

[Anonymous]

maybe a timing chain problem or give the distributor a check and make sure the gear isn't able to spin freely at all

 

[Anonymous]

If your planning to change over to a 200, I think I might a 170 bellhousing that would bolt up to your 200, doesn't have the clucthfork. Came out of a 70 maverick. Let me know if your interested. thanks
ponyboy, at ponyboy0101hotmail.com

 

[MustangSix]

Even if it needs a new crank, repairing the 250 will be cheaper, easier, and faster than a 200 swap. Drop the pan and inspect it now before you do any irreparable damage.