You need to know what diameter the bellhousing uses because that is what determines flywheel size, not the engine. You can get Gen III Hemi 8 bolt flywheels in 130 and 143 tooth, 10.5" or 11", if the 3.9 5 spd used neither, then youre screwed.
I guess I'm not being clear in explanation I suppose... I'm aware I have to use a flywheel that matches the intended diameter of the bellhousing so that the starter will engage the ring gear. The 3.9L Dakota bellhousing that can mount the MA5 transmission to the 5.7 hemi used a 143 tooth 11 inch flywheel that was odd in that it still used a 10.5" clutch. I was trying to figure out if the stock flywheel that comes on the 5.7 hemi is indeed 143 tooth/11 inch and what clutch size it uses, etc. etc. etc. The hemi uses a different bolt pattern to mount the flywheel to the crank, otherwise I could just use the original 3.9L flywheel. As to buying an aftermarket flywheel, that is always an option but if I can use something already available in a junk yard for much cheaper why pay that much?
