Scavenger 350 build, need help matching parts

[Samt]

Hey guys I'm new here to the forum. I bought a boat with a 305 that got frozen this winter. I tore it down and found a busted water jacket in the valley, other wise it was in pretty good shape.
A good friend of mine gave me a Vortec 350 that was an irrigation motor. I tore it down and found a fairly solid bottom end, block needs a hone and cam bearings. Vortec heads that need a big freshen up, trashed roller cam.

So, I'm on a serious budget, my wife isn't so sure about this boat! After I get it on the lake I may be able to upgrade some stuff, but I need a solid bottom end. The catch is my outdrive used a special drive flage that will only bolt up to the 2 piece main seal cranks. (and no they don't make one for the 1 piece crank, Its a OMC 800)

Good Parts I have
86+ 350 Block (needs freshened)
2 piece 305 crank
rods and pistons 4"
OMC marine flat tappet cam
305 heads in used, but OK shape
vortec heads that probably need $400 in work
Holley 650 double pumper
I have an intake for the 305 or vortec heads

So I'm thinking I use the 305 crank with the 350 rods and pistons
Use the flat tappet cam from the 350
Buy a main seal adapter
Get the block fixed right
Use the 305 heads and intakes for now (assuming the vortecs need as much $$$ work as I think)

My question is will this work? I guess the main variable I'm concerned about are push rod length, head gaskets matching up, Crankshaft fitting in with no mods.

I can go back in later with some better heads, maybe fix the vortecs or buy something else. They are at my machinest now to get cleaned up and magnafluxed. He was sick today so I didn't get to talk to him.

Thanks Guys I know this is a lot to ask!

[Samt]

Also wondering what gasket set to buy with this mess ? The gasket kit and bearings for the older engines are dirt cheap, I assume I use that and need different intake gasket if I run vortec heads?

[jerry clayton]

I think I still have 30 or 40 2 piece seal adapters around here somewhere-----billet aluminum originally made by K teck---I think I bought all they had as we used them to do the 2 piece seal cranks in the LT stroker engines
we built