Motorcraft 21xx carb on an AMC 258


Parts I used: Junkyard Motorcraft 2150 from a ford van, Venturi size 1.08.
Mr Gasket Adapter 1937. To get from summit search for part number MRG-1937
Old Carter BBD carb

Adapters


You may want to try a different companies adapter. The Mr Gasket adapter doesn't cover the entire base of the motorcraft carb. I just used the full thick gasket provided with my rebuild kit.

REBUILD YOUR CARB.

It doesn't take long and you can get away with using a couple cans of carb cleaner. It's easy and worth it. While you're in there replace the float. Most kits don't include this, but I feel it's a good time to put a new one in.

Carb Selection

I actually tried 2 carbs out. First I got a 1.21 carb. This is the venturi size cast into the side of the carb. This is really too much carb. Get a 1.08 carb. It's the perfect size for my 258!

Short HowTo

1. Remove your old carb, leave the linkage rod attached to the vehicle. Get rid of all the extra wiring, hoses, POS emissions computer, etc. Have fun.
2. Clean up the carb mount surface. Mount the adapter with provided gasket and hex bolts. Mount your rebuilt motorcraft carb with the linkage towards the fender. Hook up the fuel and vaccum lines that you actually need. Distributor, CTO valve, Charcoal cannister...
3. Point of no return. you may want to try running the engine with the new carb before you go the the next step.
4. Drill out the rectangular section where the linkage arm is attached to the carter carb. Once you get it far enough you may need to hit it with a hammer. Be nice to it, since you still need this piece. Now that you have the arm off, put it in a vice and flatten the end WITHOUT the ball connector for the linkage. This will make it FAR easier to mount to the motorcraft. You should still have 2 90 degree bends in the arm. Leave it like this to get an idea of where you need to mount it.
5. Now go hold your carter linkage up against the motorcraft linkage. You should have a nice ~1" long area where they meet up nicely. Look at the distance from the ball end to the rectangular hole in the carter linkage. Try to keep the same distance from the pivot of the motorcraft linkage. Once you get a good place go ahead and drill a hole and use something like a grade 8 bolt and locknut combo to hold them together. I used grade 8 allen head bolts and nylocks. Once the first is done, you can tighten it down enough to hook up the linkage rod and test out your setup to ensure that you are getting proper throttle movement. Once you're happy, drill another hole and bolt it together again.
6. Congrats. You should now have everything hooked up correctly and be ready to tune in the motorcraft to idle decently. If it idles really high, you may have a vaccum leak. Try a shot of carb cleaner at the suspect area. BE CAREFUL. THE EXHAUST MAY BE HOT ENOUGH TO IGNITE THE CLEANER if you spray it on the exhaust manifold. Have fun.