Advice needed...

HP is a measurement of how much air is pumped through the engine. That amount of air is greatly effected by displacement and engine speed. Since the 340 is 20cuin less than the 360, it would have to turn more rpm to move the same amount of air. All other variables being equal, of course. Besides I love turning rpm, it makes the panties drop!

Mathematically you'll move the whole powerband up about 300 rpm if you built the 340 to the 360 specs you have now. Plus the new cam.

Staying with the 3.55 gears ? If so I wouldn't venture to far with the cam.

Probably an xe268h or xe275hl or similar would be my choices.