[Marv D]

Somewhere between 200 and 300 would be my guess. The 262 is a horribly mild cam for any performance build, let along the big cubes of a 400. What is the 262,, something like 206° @ 0.050" ? Be very cautious that you don't build a octane hungry animal here. Most smogger era heads are 76cc chamber. 76cc, add 3or-so cc for valve reliefs in a flat top, 400 bore and stroke and your at a MINIMUM of 9.8:1 compression with a standard composit gasket. If there is any milling done to the block deck, or the heads to flatten them out, and your over 10:1 in a heartbeat. If it happens to be any of the 64cc heads your above 11:1 without a doubt. Iron heads, 11:1, a mild 262 cam is going to be a detonating SOB that you will have to run 110 octane fuel in (and I mean 110 motor octane as in a leaded race fuel ONLY). Either go back to the dished pistons and get compression down to high 8's or low 9:1 range, or get a BOATLOAD more cam, or step up to a good aluminum head. Aluminum heads pull heat out of the combustion chamber and allow you to run more compression with less octane than is acceptable for an iron chamber that holds heat. Not to mention the benifit of addef flow from most all aluminum heads. But to take advantage of a improved head your still going to want to use more cam than the little 262.

Just my 2cents