340 buildups
If the 340 has 1.88 intake valves in the heads, I wouldn't cry about it, with the specs given.
In fact, the smaller valve is going to work better for street usage, on a 340, than a 2.02 valve will, anyway, especially with the cam choices and compressions I've seen in this thread, so far.
1.88s should handle 6,000 RPMS on a non-stroked engine (Under 380 cubes), easily.
Mark.