Every one has side stepped the two posts from Grinsha. All the parts from the 307 that 65chevy20 has, will fit into a 350 block. I don't know any one that needs more than 15 minutes to find a good 350 block. Stock 327 STD-30-40-60 are not as cheap today as 350 pistons, but $150 should do it.
I don't remember ever hearing of anyone building a 327 out of a 283. Not that it couldn't be or never was done. What was very popular, was to bore the 283 to 4" and make a 301 (4" Bore x 3" Stroke). In the '60s this was very popular, because off-the-shelf 327 pistons (4") were probably $40 (guessing here). This is the engine Chevy copied with their 302 (4" Bore x 3" Stroke). Ok, 301.44 inches. This is really a great engine. Rod to Stroke ratio is 1.9 and Bore to Stroke is 1.33. The 327 is also real good with 1.75 R/S and 1.23 B/S. You can't get that with any other small block without aftermarket long rods.
The whole idea of mixing and matching parts is to save money.
