pistons

Not familur with Dykes rings, but what cylinder head are you using? With limited effort 340s can make 500HP which is pushing the envelope of the block unless you have a couple and dont mind trashing them. Then to slam on that kind of nitrous just wouldnt be a good idea. This is what you can try with stock crank and rods. If your looking at street strip look into a set of Eddy's (box stock) with a Victor or M-1, get those pistons to 11:1, either put in a Mopar .557 Mech or some cool custom Comp grind with a good 750 Holly HP and bam, you'll be happy! If you put that combo in a cool little A body with a good 904 with 3500 street converter 4:30 gears you'll bust out mid 11's all day long. Not too much money and great performance. Got to love Mopars!! No Nitrous required, and you'll have the ability to put the smack down on plenty of street cars:) Just some ideas, there are many many ways to skin a cat, this is just a known winner if you're going pretty basic. Of coarse I've very much oversimplified this, but in whole you don't have to go crazy with Small Block Mopars, they take very well to mild performance mods.
Good luck!