Forged 340 Crank in a 5.9 Magnum

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TT5.9mag said:
A pilot bearing that costs $28 bucks.
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Doesn't the 5.9 Magnum cast crank have to be machined to accept the input shaft of the A-833 4-speed?

I know there is a roller pilot bearing sold to use for this conversion as I bought one from Brewers.

If not, I thought you had to trim the input shaft of the transmission approx 1/2 " to fit properly.
 
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I’ve never done an 833 to a magnum, but I am right in the middle of doing a T56 magnum to a 5.9 magnum and it was very straight forward. From the searching Ive done it seems the 833 is a direct bolt on affair.
 
I could be wrong but I think the G3 is the only one that needs to have the input shaft cut down. I know for sure that one does, and I don't remember a Magnum needing that mod, but my memory isn't always the best.
 
TT5.9mag said:
I’ve never done an 833 to a magnum, but I am right in the middle of doing a T56 magnum to a 5.9 magnum and it was very straight forward. From the searching Ive done it seems the 833 is a direct bolt on affair.
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I have a A-833 4-speed on my 408 Magnum Stroker. I didn't need to do any crank modifications, just used the roller pilot bearing you mentioned. But, I seem to recall when talking to Brewers that they mentioned to check the crank to make sure it was drilled deep enough for the input shaft of the 4- speed.

Cheers!!
 
Super-Cuda said:
I have a A-833 4-speed on my 408 Magnum Stroker. I didn't need to do any crank modifications, just used the roller pilot bearing you mentioned. But, I seem to recall when talking to Brewers that they mentioned to check the crank to make sure it was drilled deep enough for the input shaft of the 4- speed.

Cheers!!
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I've for sure heard of issues where the OD isn't right for the oilite bearing to press in. And it does seem like sometimes if the crank isn't finished for the bearing that it also isn't drill deep enough. But it's more of a feeling than a definite memory. :)
 
DionR said:
And it does seem like sometimes if the crank isn't finished for the bearing that it also isn't drill deep enough. But it's more of a feeling than a definite memory. :)
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this is very much true for LA engines in that some cranks are drilled for the 4spd input and some are not-- a mistake of not checking you'll only make once...

i don't know if they changed that and all the magnum engines are drilled, but i've yet to find one that wasn't.
 
That 340 crank would drop right into a 318 magnum... Just sayin
 
junkyardhero said:
but you sure could brag about having a forged tree-fordy crank in there and the bill from the balancing shop to prove it!
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That would carry a lot of credo with the Chevy guys.
 
junkyardhero said:
i think i'll make a run at doing that next time. after all if we're not here to impress the chevy guys what are we even doing?
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Yeah cause that don't take much. All you gotta say is "thee fiddy foe barrah" and they all stand up and salute.
 
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TT5.9mag said:
And wouldn’t make much difference.
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junkyardhero said:
but you sure could brag about having a forged tree-fordy crank in there and the bill from the balancing shop to prove it!
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Never said it would make much difference. Just that you could. And the "Bill from the balance shop" wouldn't be necessary because they would have the same internal balance as the stock 318 magnum crank had. And before you say '72-3 external balanced version 340 crank, those weren't forged no more. Those were cast.
Honestly I was looking something up once I. A crank kit book at a car quest some years ago and I kid you not the crank from a 318 went from at least 1967 (maybe earlier, ) to well Into the 90s. Same crank casting number. So no rebalance would be needed. Actually there were some 318s built in the 70s with forged cranks/ although not many. These were HD truck and industrial ones.
As far as the original question it wouldn't work because the 360s always had a bigger diameter main bearing than the 273-318-340
 
volaredon said:
Never said it would make much difference. Just that you could. And the "Bill from the balance shop" wouldn't be necessary because they would have the same internal balance as the stock 318 magnum crank had. And before you say '72-3 external balanced version 340 crank, those weren't forged no more. Those were cast.
Honestly I was looking something up once I. A crank kit book at a car quest some years ago and I kid you not the crank from a 318 went from at least 1967 (maybe earlier, ) to well Into the 90s. Same crank casting number. So no rebalance would be needed. Actually there were some 318s built in the 70s with forged cranks/ although not many. These were HD truck and industrial ones.
As far as the original question it wouldn't work because the 360s always had a bigger diameter main bearing than the 273-318-340
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If the pistons/rods get changed the bobweight will change and the crank needs balanced. Regardless of which crank it is. Internally balanced or not. As far as the original question, it’s been answered, it WILL work with the bearing spacers and a balance job but will gain nothing over a stock crank. So there’s little point in doing the work.
 
volaredon said:
.... the "Bill from the balance shop" wouldn't be necessary because they would have the same internal balance as the stock 318 magnum crank had. And before you say '72-3 external balanced version 340 crank, those weren't forged no more. Those were cast.
Honestly I was looking something up once I. A crank kit book at a car quest some years ago and I kid you not the crank from a 318 went from at least 1967 (maybe earlier, ) to well Into the 90s. Same crank casting number. So no rebalance would be needed. Actually there were some 318s built in the 70s with forged cranks/ although not many. These were HD truck and industrial ones.
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while i am well aware of the differences and break downs of 340 cast and forged cranks (i've owned a few) and 318/273 forged and cast (again, owned a bunch), the fact remains that if you change the pistons and rods, you're likely going to need to rebalance-- and that would be 100% true if you were using magnum components with the earlier LA crank because those pieces are lighter.

i don't doubt that the 318 crank carries the same number for years and years, but just because it has the same PN doens't mean it's the same piece.

could you just throw caution to the wind and grab any ol' 318 crank and snap on some rods and pistons-- magnum or not? sure, you could. i don't know why you would unless you're trying some bobo *** uncle tony nonsense. which is fully your prerogative, you made that money spend it as foolishly as you see fit.
 
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