You could take a 455 and re-ring and bearing it using all stock parts, add a small cam, intake and headers and it will outrun 99% of most 350's. Its not complicated for sure!
I wish you would have kept going with your 350 project. You would have at least done a lot more than the talkers on here. Hey, it has been a whole summer now and no new comers to the track. I take that back, we got Demko to go to the track. There has been some others working a 350 but I think they just stay away from here. Too bad, I like to hear results of progress with a 350. Not what if's. I understand, the 455 is just too darn easy to make power. Give it a cam and headers and it will beat most 350's for sure but I have smacked around a few in my time. and don't say, "just only the stock ones" stiff, LOL.
Who knows, I may eventually build the 350 just for grins and giggles, I was looking forward to what kind of power I could make with it. I'm keeping all the parts to it, If I can find a block someone is willing to let go for next to nothing it's a real possibility. If my block didn't turn out to be bad I would have built it.
Well ,when I started this car , I had a ET goal in mind. Being I am up in Denver , I knew whatever I built would be a second slower than at sea level Since most 350 combos run mid 13s at lower elevation , with a few running12s , I would be lucky to run hi13s up here. Plus I am using exhaust manifold as well. Hell if a sorted out Superstock combo runs 11.0s in good air with headers, ill be lucky to run mid 13s up here probably hi 13s realistically. That's not where I want to be But hey, its al good Hope all is well; Guy
In your case if you don't have to abide to any sanctioning class type rules then opening up the bores and lengthening the stroke should help get you to the finish line sooner than the typical 355 CID guy. With an extra 30 CID to get a sbb 380 things would get easier to achieve faster QM times. Opening up the bore .100"+ would go a long way to help unshroud the sbb valves while an extra .140" stroke would give the 380 more time to fill the cylinder with the extra flow from the unshrouded valves. Sonic test a couple of blocks, maybe you'll find one good enough to take to a 4.00" bore that would make it a 401 with a 3.990" stroke! With that much unshrouding if the heads that are well ported it should run REALLY well down the QM being 150 lbs lighter than a BBB with an aluminum SP3 on top, even lighter when the aluminum heads come out and they were added, even at a mile high. Derek