Hi I'm new to this forum ,and I just have quick question does anyone know if
225 slant 6 main bearings for a cast crank will fit a forged crank? Cheers.

No. Cast bearings are narrower.

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Official Cookie and Mater Tormentor.

Correct, same for the rod bearings too.

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-MattMan
LEANED & MEAN

Hi thanks for the quick reply,but now I'm more confused because on this article /Each engine has a different crank. The 170 is PN 2843941, the 198 is PN 2951979 and the 225 is PN 2899582. They all have the same main bearing journal diameter of 2.750" and also the same crank pin diameter (rod journal diameter) of 2.189". They also all have four main bearings. While the 225 crank will fit in a 198 engine (with the correct rods), the 225 crank will not fit in a 170 engine - it interferes with the block. The 1976-77 forged crank for the 225 is 3830099, while the cast crank is 3751036. The cast crank is not interchangeable with the forged crank. The forged crank was phased out of production at the end of 1976. The cast crank engines can be identified by an "E" stamped next to the engine number (i.e. 225E).

The best crank to use for heavy duty six cylinder applications with the 225 engine is the 225 truck crank which is shot-peened. The number for the trucko crank is 2899582 (with pilot bushing).

In 1968 the slant six's crank flange was changed. The flywheel pilot and torque converter nose diameters were enlarged on the newer cranks. These cranks are interchangeable except for this. The '68-69 large pilot crank for the 170 engine is PN 2843941. The 198 and 225 listed above are large pilot cranks.

The reason I'm asking is because I have a forged crank and am having trouble
Finding main bearings. 040 oversize.

Simon; All slants had a 3.400" bore. Mopar played with the crank throw and rod length, as well as deck height to get the different cubic inch displacements. The 170 had a deck height about 1" shorter then the 198 and 225. The main and rod bearings for all forged crank engines will interchange, while the same holds true for mains and rods between cast crank engines.

You say you have a forged crank.....is it original to the block you have?
If so, what you need are bearings for a slant six from 1960-1975.

You might try Rockauto.com

Roger

Any particular reason you are set on this size? Which forged crank do you have (170/198/225)? I could understand keeping the one you have or having a hard time finding a replacement crank on the 170/198 (they are out there)... but on a 225 if this were a daily driver or a seriously wornout crank, I'd be tempted to go with a crank kit and just get one that was 10/10 and all the matching bearings.... or find another core crank and check it for wear and go from there...

What are your intentions for the engine build?

It will be hard to find bearings in .040" under. .030" is usually as far as anyone goes.

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Official Cookie and Mater Tormentor.

Yes it's a early slant 6 with 5 welch plugs,financially I need to stay with this
Crank,and you wouldn't beleave how places I've tried both here in Aus and there in the US.i found some main bearings for a slant .40 oversize on eBay but for a cast crank 77-86,I'm getting desperate.

You can get crank/bearing kits for around $200 or so from most any parts store.

Has yours already been ground?

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Official Cookie and Mater Tormentor.

Yes it's been reground 4 times because of oil issues and some bad advice.

Does anyone know the width of cast crank main journals or bearing shells?

I can measure a set later today.

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-MattMan
LEANED & MEAN

Cool thanks

Where in Washington are you? Someone might have a crank to get you out of your pickle.

I would sincerely hope that a machine shop wouldn't grind a crank to an undersize for which there are no bearings. I might ask them to grind another crank for free or at least a substantial discount.

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Joshua