Anyone recommend a 305 - 335 stroker ?

There is only one way to arrive at that displacement with a 305. You get a specially machined 400 crankshaft, rods, and pistons to match, bore your engine 0.030 over and use most of your stock parts. This is how you take a 350 and make it a 383, the difference is you start with a 350 block.

Your 305 has the same crank and rods as a 350 from the factory. The difference is the 350 has a 4 inch bore, and you can't bore a 305 that big.

I would have somebody mike your bores to see just how worn they are before buying anything. I found that if I tried to get away without boring an engine while I had it apart, it was only a couple of years before I wished I had bored it.

Don't think there is enough 'meat' in that block to do much modifications. You'd be much better off finding a 350 or even a 327(scarce) to gain power and long-term dependability. The 305 block is just not a strong unit. s