71 340 Compression Test

You are in the wrong box again.lol
Think 325 hp plus 125nitrous.
Nice smooth 15/20mpg cruiser-engine, and 450 to bust everything behind the engine with. Keep your savings account topped up;Nitrous has a bit of a learning curve.
The 480* is too big, especially if it is a slow lober. 268 to 276 is more street friendly. But again, if you pick the cam before the SCr is in, you may have to spend more money adjusting the compression for the cam. A cruiser cam will often be less than 268, unless you just can't live without the lope. The factory 340 cam was 268/276/114 with what today would be considered very low lift.And it had just 44* of overlap; perfect for a cruiser with manifolds, but not so good for headers.But possibly good for nitrous.The factory 360 2bbl cam will absolutely shred tires,off-the-line, with a little compression.
And I repeat, get the fastest lobes you can find. These are sometimes called fast-rate cams, or hi-intensity. Some manufactures are able to put a lot of lift on these, others not so much.Get your monies worth. Nitrous cams are usually different from NA cams, although some can serve double-duty.

But you know what, all this talk is just talk.
If your engine is otherwise healthy, it is already a great cruiser engine, AND it is a pretty good candidate for nitrous. You could be a 383 slayer,real quick.
Right until the bottle runs out.................You probably want the extra-large size,lol