Is my crank drilled for a 4 speed?

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MidnightSwinger

MidnightSwinger

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I’m just getting into my 4 speed swap and I thought I would have to drill the crank/cut the input shaft. But it looks like I’m set up for 4 speed, can anyone confirm?

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This is the depth from the very outside of the crank flange/TC snout.
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Thanks,
Jared
 
What is 22mm? Like 7/8"? Seems a bit shallow to me.
 
It looks like it has a pilot bushing in the crank. Measure from back of block to inside of crank then measure bellhousing to end of input shaft, that should give you your answer.
 
moparlvr166 said:
It looks like it has a pilot bushing in the crank. Measure from back of block to inside of crank then measure bellhousing to end of input shaft, that should give you your answer.
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It’s got a bushing and the od measures (roughly) .965” I’ll definitely do some more measuring when I get more into the swap. Thank you.
 
MidnightSwinger said:
It’s got a bushing and the od measures (roughly) .965” I’ll definitely do some more measuring when I get more into the swap. Thank you.
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That's why I wanted to be sure of the depth. From the picture, it's deceiving and does not look that deep. Remember, some folks make manual transmission cranks out of auto cranks by installing a bushing and cutting some of the input shaft off. With your measured depth of over 2", I do not believe that is the case. I think you are good to go.
 
RustyRatRod said:
That's why I wanted to be sure of the depth. From the picture, it's deceiving and does not look that deep. Remember, some folks make manual transmission cranks out of auto cranks by installing a bushing and cutting some of the input shaft off. With your measured depth of over 2", I do not believe that is the case. I think you are good to go.
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I didn’t want to get my hopes up but after getting the depth measurement I was fairly confident that I had a 4 speed crank. It’s a 70 HP 383, so it falls in line with what I have heard;forged cranks were drilled for 4 speed.

I always appreciate the help y’all!
 
MidnightSwinger said:
I didn’t want to get my hopes up but after getting the depth measurement I was fairly confident that I had a 4 speed crank. It’s a 70 HP 383, so it falls in line with what I have heard;forged cranks were drilled for 4 speed.

I always appreciate the help y’all!
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I believe you are correct sir! Happy motoring!
 
MidnightSwinger said:
............what I have heard;forged cranks were drilled for 4 speed.............
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FWIW, my 440 automatic forged crank has the 4 spd depths. The bushing bore diameter is undersize for the stock bushing.
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If it helps.............

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Mine had a bushing in it as well. But the OD of the bushing was smaller. There used to be an undersized crank bushing to be used with automatic cranks that were drilled, but not honed to final size. I couldn't find one for sale anywhere, so I ended up using a pilot bearing that fit into the torque converter register.

I believe my crank had an ID of about .910, and the bushing is like .960 or something close to that.

20221230_105120.jpg
 
Just to add a data point, the crank from my 79 360 factory auto is drilled deep enough for a 4-speed. As best as I could measure, it was 2-35/64" deep measuring all the way to the bottom of the hole.
 
In my opinion, there is only ONE way to find out

...Install, even temporarily, the bell/ scattershield on the engine and measure from the transmission mounting surface to the bottom of the hole. Then measure from the end of the gearbox shaft to the mounting surface
 
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