Which edelbrock intake and what stock manifold are you swapping out? Performer 318/360 is a junk manifold. A stock Iron 340 intake is better, especially if you put a 1" spacer on it

A 2.02 valve headed 340 with a xe268H will make about 350hp with everything right. 340's will really have something along the lines of 9.5-9.7:1 even using higher compression 68-71 pistons.

I'd like to see that Dyno Derby 395hp, 340, run on the dyno at Indio Motor. No chance it makes 395.

Just as a side note. I've seen at least 6 engines, 340-360, all built with the same basic package, 9.5-10.5:1, stock heads good valve job, xe268H, air gap/LD340, 670-950 carbs, headers and none of them made more than 360hp, most made between 335-350hp. The ones that ran at the track all MPH'd like a 330-350hp engine per weight.

The XE268H is a good all around camshaft.