OK, now we're getting somewhere. Just to be clear, 351W 2V and 4V heads are exactly the same. The 2V/4V head and open vs. closed chamber distinction is a Cleveland thing.
Stock '69 351 4V compression, with the factory flat top pistons is 10.7:1.
I have no idea what your cam specs are, but if its a typical street performance grind, I can tell you from experience that combo will ping on modern pump gas. You'll need to add octane booster, some race fuel, or retard the timing in order to make it live. If you've added aftermarket pistons or opened up the chambers to reduce the compression to 10.075, you'll be right on the edge with iron heads and pump gas.
In my case, adding some aluminum twisted wedge heads (61cc chambers) was enough to stop the detonation when running premium pump gas. Although the compression may have dropped a fraction, its the superior heat dissapation of the aluminum heads that really makes the difference. That said, I'm running a manual transmission with fairly steep gears, and don't lug the engine. With an automatic (unless it has a very loose stall converter and 3.50:1 or higher numerically rear gears), I'd want to drop the compression down to 10:1 or below to be on the safe side, even with aluminum heads.
One other often overlooked factor is spark plugs. The factory 351W 4V plug was an Autolite (now Motorcraft) BF32. The period "performance" plug recommendation was a BF22. Standard 2V Windsors used a BF42. The larger number indicates a hotter plug, meaning it doesn't dissipate heat as quickly. Almost all the modern day spark plug reference charts list a single replacement plug for the '69 351W, which is the BF42 or equivalent. Those plugs are too hot for a high-compression engine, and will contribute to pre-ignition. If you're running the factory iron heads, its worth the effort to seek out the cooler running equivalents to the BF32 or 22. Newer replacement heads use smaller plugs, so the numbers will be different, but its still a good idea to make sure the plug heat range is appropriate to the compression ratio.
I hope that helps a little bit.