I just purchased an old Chrysler adapter kit to mate a slant to a smallblock trans. I know the crank hub and torque converter snout changed sizes in 68, my research indicates that the big 68-up torque converter hub is 1.8 inches outside diameter. I took a couple measurements on the crank spacer to see what kind of machine work would be necessary to get it to work with a 68-up transmisison. Here are the numbers:

Snout that goes into the crank hub= 2.158 inches outside diameter
Pocket that slides over the torque converter snout = 1.951 inches

If all the above is true, then I shouldn't have to machine anything to get this adapter to mate to a 68-up crank and 68-up torque converter, right?

You need to machine.

You have it bass akwards.

Darn. I have to go double check my measurements and then find a shop that can do some quick machine work. I guess I also need to get one of those adapter rings to use a later engine on an earlier transmission.

So I am measuring the wrong dimension in each of these pictures? Should I be measuring the inside diameter of the ring that protrudes from the spacer in the first picture?

Duh, I have been visualizing this wrong. It has been too long since I looked at the end of the crank on a slant. The flex plate installs over that raised ring and the torque converter snout plugs into that same ring. I DID measure one wrong dimension because I thought the spacer installed 180 degree of from what it actually installs. Got it.

What do you think? Still need to machine?

I believe 1.81" is the big converter snout. You should be good.

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Official Cookie and Mater Tormentor.

Yes, that is the big snout so that will fit a late converter (1.815" is spec, IIRC). However, the other end needs to fit over the end of your crank hub and that is the small size from your earlier picture. Make sure to check all this by fitting up to the parts you have, but I am pretty sure you need to machine the ID of the other end to fit your big hub crank (assuming you want to run a big hub crank).

Lou

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Home of Slant6-powered fun machines since 1988

You should have a CAD file made of the often missing spacer.

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1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

(1) I am a bit of a slant snob, and I only run large crank slants. Seriously, I don't want the headache of the small crank hub issue, so I don't mess with any pre-68 motors. I will double check the measurements of the crank hub and the spacer. I have some loose 80s era cranks but my garage is crammed with home remodelling items right now and I can't reach them.

(2) CAD? I would be happy to loan the spacer to someone who has the equipment and knowledge to make a CAD file, but I don't have a clue how to do CAD. I would need a solid guarantee that I would get the spacer back, too.

I cruised my local pick-n-pull yesterday during a 40% off sale hoping to find an A500 in a 90 Dodge van they had. No luck. Just a regular 904. I will keep looking.

Someone already has the AREngineering machining patterns and computer files, but since no one
can get enough people together to make another run they probably will never get used again.

FYI.