72 duster 4spd swap

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aaron68s

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hey guys. I'm changing my 72 340 duster to a 4spd, is there anything special i need to do to the crankshaft? its a forged crank factory auto. im also looking for a good clutch and flywheel setup and hurst shifter linkage rods. thanks for any input.
 
The crank may not be drilled deep enough and the trans input shaft may bottom out. Mount the trans to the bell and measure the length of the shaft then, measure from the rear of the block to the depth of the hole.

I'd use the pilot shaft roller bearing.

Centerforce II clutch, pp, and bearing.

Brewers or Passon performance has all of the shifter parts ya need or post a parts wanted ad.
 
pntastar69 said:
The crank may not be drilled deep enough and the trans input shaft may bottom out. Mount the trans to the bell and measure the length of the shaft then, measure from the rear of the block to the depth of the hole.

I'd use the pilot shaft roller bearing.

Centerforce II clutch, pp, and bearing.

Brewers or Passon performance has all of the shifter parts ya need or post a parts wanted ad.
Click to expand...
thank you for the help i appreciate it
 
Information: Many years ago I built a 318 out of a auto something (I don't know what) to swap into my Dart sport 318 3-speed so it would be a 1 day down time.

Guess what! The pilot bearing wouldn't fit! I went to the dealer to get a smaller diameter pilot bearing and they told me that there was only one size. It seems that MOPAR didn't always machine out the crank on auto cars for the pilot bearing. (or that was the story I was told at the time)They had drilled the hole but didn't machine it out all of the way.

Good news, As I was staring in disbelief at my assembled and painted engine I picked up a lifter out of the old engine and stuck it into the end of the crank. (It's a guy thing) Anyway it fit perfect. So I took the pilot bearing down to a machine shop and had it turned .005 larger than the lifter. Perfect interference fit. Has been going for 200k so far. I am about to change the clutch so I hope it is still OK

You might want to check the crank when going from a auto to a stick as the dealer also told me that some of the cranks they didn't even drill out. (saved a machining operation I guess)

Hope this helps.
 
kt340sport said:
I would think the forged crank would be drilled to accept the pilot bearing.
Click to expand...

I would tend to agree. But if its not, there's an easy solution. This is a roller bearing that fits into the outer register on the crank instead of the inner one that may or may not be drilled on an auto crank.

PB5300-1.jpg


Then you just trim down the end of the input shaft on the transmission, as the bearing rides further back on the shaft anyway. Brewer's and plenty of other places sell them.
 
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