swany said:
Pretty sure you will need a 26 inch mag tube from a model 64 Winchester essentially a model 94 with a pistol grip.
Change over from bbl bands to fore end cap and dovetail attachement for the mag tubes fwd mount.
The Model 64 Winchester had a half magazine, and 24" barrel. More to the point, what 38-55 barrel did you get. If it's a Winchester left-over, it probably has all the dovetails you need. Aside from the magazine issue, I believe there will be a problem with the cartridge guides, the 30-30 being a bottle-necked cartridge, while the 38-55 is essentially a straight case.
I'd bring your question to the folks at
http://www.levergunscommunity.com. There are several Winchester 94 experts there who will probably be able to walk you through the conversion.
Hope this helps.
Mike