Is the 351w going into the 95?
Here is what I see you needing...
Cowl hood (in order to run the van intake manifold. you could swap intakes, but that will cost ~$500+)
Oil pan - you need a double sump pan for the Fox, I don't think the vans had a double sump???
Headers - Getting shorties to swap directly in place of the stockers you have now will be easiest... I think MAC still has the cheapest set out there???
CAMSHAFT - This is where things get tricky... The 92 block is not a roller block. You will need the $$$ link bar lifters, at ~$450.
Or you can run a reduced base circle cam, but they are prone to causing other valvetrain issues... this is a bad option...
The camshaft out of the van will not likely be compatible with your ecu (check the firing order of the van against your 95GT).
The swap should be doable for ~1k to $1,500...
jason