manual vs Automatic crankshaft

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Rakers_SS

Rakers_SS

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Hello everyone,

I just ordered a rebuilt 360 that'll be delivered in a few months and had a quick thought I wanted to run past the experts. Are the crank on the manual and automatic cars the same? I'm planning to use the 3 speed from my duster for now and eventually upgrade to a four speed down the road. I just want to make sure I'm not going to have an engine show up with a crankshaft that I can't use...

Appreciate any advice!
 
I've never used the needle bearing type, I've always used the solid ones...I'm sure somebody with more experience with them will chime in...
 
Not sure about all 360's but not all small block cranks are machined for a pilot bushing but all can be retrofitted with the newer style pilot bearing that presses into the area where the torque convertor snout fits into. You might have to shorten the input shaft of the transmission around 3/8 to 1/2 inch to allow the transmission to fully seat against the bellhousing.
 
No they are not the same at all. The manual transmission crankshafts are drilled much deeper to accept a bronze pilot bushing. The automatic crankshafts are not drilled near as deep. They usually require you to trim about 3/4" off the end of the input shaft and also require a different style pilot bearing that presses into the crankshaft register. Normally, forged cranks are drilled for the pilot bushing and cast cranks are not. Also, the cast cranks generally cannot be drilled because you will run into the oil passage as the crank is made completely differently from the forged crank. That's why the input shaft has to be trimmed and the different style pilot bearing must be used.
 
This is what you want if its not drilled. We used the one below in my dads forged crank 440 because the manual pilot wasn't finished and we knew it cam from an auto car. As said above, you'll need to shorten the trans input shaft.

Mopar Performance Pilot Bearing

I know on a 360 we built for a guy we used a thinner brass bushing that NAPA sells.
 
RustyRatRod said:
No they are not the same at all. The manual transmission crankshafts are drilled much deeper to accept a bronze pilot bushing. The automatic crankshafts are not drilled near as deep. They usually require you to trim about 3/4" off the end of the input shaft and also require a different style pilot bearing that presses into the crankshaft register. Normally, forged cranks are drilled for the pilot bushing and cast cranks are not. Also, the cast cranks generally cannot be drilled because you will run into the oil passage as the crank is made completely differently from the forged crank. That's why the input shaft has to be trimmed and the different style pilot bearing must be used.
Click to expand...
Rusty, I have seen plenty of cast cranks that have pilot busing from the factory, it does not make sense the factory would make two cranks for the different trans.
For the op it will be hit or miss on the engine you bought.
I have a 72 340 in my duster, cast crank, it is drilled for a pilot bushing.
I also have another 72 cast crank 340 in my building that is not drilled.
I also have a 360 cast crank that has a pilot bushing, and a mag 360 that came out of an auto, but the crank was drilled for a bushing.
And a 74 318 that is not drilled.
70 340 with the bushing, but it came out of a 4-speed car, I parted out.
 
If you end up needing to drill it, don't go too far. Guy I know drilled right into the oil passage once.
 
OK, thanks for the input everyone! sounds like either way I'll be alright with either trimming the input shaft slightly or getting lucky that it'll have a manual crank. I'll give the builder a call and specify a manual trans crank and see what he says. Thanks again!
 
sireland67 said:
Rusty, I have seen plenty of cast cranks that have pilot busing from the factory, it does not make sense the factory would make two cranks for the different trans.
For the op it will be hit or miss on the engine you bought.
I have a 72 340 in my duster, cast crank, it is drilled for a pilot bushing.
I also have another 72 cast crank 340 in my building that is not drilled.
I also have a 360 cast crank that has a pilot bushing, and a mag 360 that came out of an auto, but the crank was drilled for a bushing.
And a 74 318 that is not drilled.
70 340 with the bushing, but it came out of a 4-speed car, I parted out.
Click to expand...

They have to COME that way. You cannot convert one. The factory cast auto cranks cannot be drilled deep enough.
 
Demonic said:
If you end up needing to drill it, don't go too far. Guy I know drilled right into the oil passage once.
Click to expand...

Exactly. This is what I am trying to get across. But hay, it's not mine so drill away. Don't come back whinin about it when you drill into an oil passage and have an oil leak right out the back of the crank. You've been warned. lol
 
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