[valiant67]

Welcome to Allpar.

The bolt pattern of the block and transmission did not change from LA to Magnum. The one thing that may be different is that even though both were externally balanced, I believe the balancing is different between the LA 360 in the 1979 and the Magnum 360 (5.9) of your donor truck. Hopefully someone else can confirm or deny that.

 

[TWX]

I believe that the balancing issue is correct.

You'll probably need to call around to find a machine shop that can properly add balancing weights to the torque converter, or see if someone has an aftermarket pre-balanced converter for sale already.

 

[tfinley]

Both of the transmission a manual, but the balance my be different on the fly wheels?

 

[valiant67]

Both of the transmission a manual, but the balance my be different on the fly wheels?

Correct. I think there is more exterior balance balance weight on the LA 360 than the Magnum 5.9.

 

[MoparNorm]

Also..CHECK your input shaft diameter and length!
While you have taken everything from the flywheel back, the pilot shaft hole size in the crank may be different. Advanced Adapters and others make bushings and kits to correct that.

 

[tfinley]

Ok thanks I will try them. I think it might be easier to change the gears in the rearend!!