350 to 383 swap questions

[Tomahawk30]

We are kicking around selling my son's 69 GMC short-stepside 4x4 project and putting the proceeds into the "new" 70 c10 swb. The stepside has a 383 and manual transmission, and the c10 has the 350/th350 out of a van. Not sure of what year of van the drivetrain came from (going to dig into it a little more this weekend), but I'm thinking seriously about swapping engines before selling the stepside.

So my question: Would a presumably stock th350 out of a van be at all useable behind a 383, even if only for a year or so (until I have the funds to either have the th350 rebuilt or buy a good overdrive transmission)? I have no idea how the 383 was put together or what kind of HP or torque it makes (certainly isn't a radical build based on what little I've driven it), but I would assume it is considerably more than the stock 350 would have made. Would I just be asking for headaches by doing a straight 350 for 383 swap without totally rebuilding and beefing up the th350?

Any thoughts, opinions, suggestions, criticisms, or witticisms are welcome and appreciated!