Crankshaft

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I am pretty sure that they are different and there is no knockout. The 4-spd crankshaft has a smaller end that will not take the diameter of the front hub from the converter. :-(
 
The only difference on the 273 crank....auto vs. manual.....is the manual crank went through a final machining process to finish the end of the crank for a pilot bushing. The hole for the converter button is the same for both. Now if you're swapping a '64-7 crank into a '68 and newer automatic, you'll run into diameter problems but that has to do with year, not manual vs. auto.
 
Well well well cudamark, you figured out my problem precisely!!!
Now would you happen to have a solution to my dilema?
 
so in effect I am correct that there is no manual and auto difference except the pilot bushing for the manual.. It's all about the years. Right?
 
cudamark answered it the best to my knowledge, I really didn't know about it until I tried to use that crank on a 69, 904 trans
 
63dartman said:
so in effect I am correct that there is no manual and auto difference except the pilot bushing for the manual.. It's all about the years. Right?
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Ding Ding Ding!!! We have a winner. The crank hub diameter got bigger in '68. The '64-'67s had the small snout and '68 up had the big snout. Throw in the fact that the input spline count on the auto trans changed in '68 also, and you have a can of worms. There are 2 ways to make things work. Keep your small snout crank and find a '66-'67 converter and trans, or find a '68 up 273, 318, or 340 crank and use the trans/converter you have. You could also have a converter made with the '67-back snout and the '68 up input spline count. Me, I'd be looking for a 318 crank. There's lots of them out there, they are cheap, and until '73 they were forged. Cast or forged the '18 crank will get the job done and will be internally balanced. Hope this helps.
 
grumpuscreature said:
Ding Ding Ding!!! We have a winner. The crank hub diameter got bigger in '68. The '64-'67s had the small snout and '68 up had the big snout. Throw in the fact that the input spline count on the auto trans changed in '68 also, and you have a can of worms. There are 2 ways to make things work. Keep your small snout crank and find a '66-'67 converter and trans, or find a '68 up 273, 318, or 340 crank and use the trans/converter you have. You could also have a converter made with the '67-back snout and the '68 up input spline count. Me, I'd be looking for a 318 crank. There's lots of them out there, they are cheap, and until '73 they were forged. Cast or forged the '18 crank will get the job done and will be internally balanced. Hope this helps.
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Good info and advise!!!
Anybody got 318 crank lying around?
 
belmateo said:
Good info and advise!!!
Anybody got 318 crank lying around?
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I've both a cast and steel crank for a 318. $75.00 and $100.00 respectively for one that will need to be ground. UPS on top of that. If your engine is still good, complete, running and you just need to mate it to a '69 904 converter, I'd just have a converter built for it. My local builder does them for about $75.00. If your motor is apart, then sure, go ahead and change the crank but you should do a full engine balance to do it right.
Thanks, Mark
 
I agree on the balancing thing. The piston rod assemblies on 273's are lighter than the 318's are. It will bolt in and it will run but it may be quite a bit out of balance.


Chuck
 
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