72 FJ40 Engine and Transmission Swap from 85 BJ70

Joined
Apr 20, 2015
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4
Hi,

I am swapping out the engine from a 72 FJ40 for a 3b from an 85 BJ70. My question is, what will I need to do to install the transmission on the FJ40 frame? Do I need to cut the current cross member in the FJ40 and replace it with something else? The cross member from the 85 BJ70 was not in good shape.

Any help would be amazing!
Thanks
Scott
 

pjohnson

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Jan 15, 2003
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Idaho
The best option is to re-use the BJ crossmember and modify it to fit the FJ40 frame. Otherwise you're looking at fabricating a complete crossmember. You may not have to remove the torque tube from the FJ40 frame as the 3B engine is shorter than the F engine.
 
Joined
Apr 20, 2015
Messages
4
The best option is to re-use the BJ crossmember and modify it to fit the FJ40 frame. Otherwise you're looking at fabricating a complete crossmember. You may not have to remove the torque tube from the FJ40 frame as the 3B engine is shorter than the F engine.
Hey, Thanks for the quick reply.
The cross member from the BJ70 was rotten. other than trying to find a cross member in ok shape, If I were to fabricate one would there be any general rules ie thickness of steel, bent pieces vs welded?

Thanks
Scott
 
Joined
Apr 21, 2005
Messages
20,696
Source a crossmember from a 8/80+ short or mid wheel base 40 series. While not as early as 72 the 3B and four speed or five speed were available in the BJ42. Good chance the torque tube behind the transfer case will need to be modified. 9/72+ could probably make it work without a hand brake on the transfer case.
 
Joined
Sep 23, 2016
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Location
Bethel Minnesota
Well I’m doing almost the same swap, my 3B came out of a BJ60.
Place the 3B forward so the transmission s*** tower lines up withe cranny cover original hole.
Sourced my transmission cross member along with the correct engine mounts from Dan at 4wheel auto in Canada.

Cruiser brothers use to have the OEM hand brake kir for the rams free case.
 

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