Clearance for a 340 Stroker Conversion

And just to be clear, OP did not mention what type of "stroker conversion" he's considering- the bigger the stroke increase, the more likely it is some mods will be needed and the more aggressive the mods will need to be.
Different manufacturers will vary in the sizes and shapes of their parts, so things like cranks, rods and pistons will need varying degrees of modification, or none at all. Individual blocks vary, too.
This is why trial assembly is essential, as no two builds will have the same needs to address.