It means you could have a 352, 360, or 390 engine, although I'd probably guess it's a 352 or 360. When you pull the engine down and micrometer the bores, if it has a 4.05" (4.08 w/ your overbore) bore with a 3.5" stroke, you have a 360, and 4.05(+.030) bore with a 3.78" stroke for a 390. A 352 will have a 4.00" original bore with a 3.50" stroke.

360's commonly had 410 pistons in them which sit way down in the bore giving a fairly low compression ratio in the ballpark of 7:1 - 7.5:1