1973 340, want more power.

First I'll address the stroker issue. Stroker's really don't make much HP over non-strokers. Stroke = torque. When you stroke an engine. It helps it make more torque, maybe a tad more HP. The biggest benefit to a stroker is that you move the entire power band down, which is a function of the new torque. So while a 340 and a 416 might both make 450 horse. The 416 will make it lower in the RPM range, and with more torque. While the 340 will make it higher up and with less torque in the bottom end. Strokers emulate big blocks. Because of this, the stroker is also an easier street engine. It will make power where you are more often (under 4k rpm), and you won't have to crazy cam it to make it run. Eliminating vacuum problems, high idle problems, gearing, etc etc. That come with a big cam small block.

Now, for a 450 horse 340, it's really not that difficult. I run a (aprox) 420 horse 340. And it's a seriously simple build.

340 - .040 over bore
Keith black 243 pistons
10.05:1 SCR (static compression ratio) - 7.45 DCR (dynamic compression ratio)
J heads, opened to 2.02 int valves, light bowl/turn work
RPM Air gap
Holley 670 Street avenger (soon to be FItech EFI)
Comp XE274H cam
Rev-n-ator ignition
Hooker 1-5/8 headers, into 3" exhaust with dynomax bullets

Nothing special at all. When it was built the builder rated it 400 horse with the 340 hi-performance exhaust manifolds. It had a 2-1/4" exhaust on it. I figure headers and 3" exhaust gotta be worth 20 horse. This is enough to motivate my 3400lb scamp into the mid 12's. This winter I will be doing the following.

Full port work - looking to get 260cfm
Solid roller cam - probably in the high 230/low 240's - around .575-600 lift
1.6 hughes rockers
Increase DCR to 8:1 maybe a little higher (my elevation is 3000ft).

With that, I am aiming for 475 horse. If I saw 500 I'd be excited. Building a high horsepower small block is not a HUGE undertaking. But it takes time. The most important thing is to sit down, figure a plan out. Then go for it. The components must match (as others have mentioned).

I'll also say this. Figure out what your car can do right now. Have you raced it? Do you know how fast it is? Why do you want more power right after you got it? Is it not powerful enough now? Why aim for the same power as a 6.4l srt? What car is the 6.4 in that you want to be as quick as? Remember, A bodies are very light (low 3,000 pound). 420 horse in my scamp has absolutely made my friends **** their pants on several occasions. Figure out your car, before you change your car. You don't even know your rear gear ratio. If you suddenly drop a 450 horse 340 and it's got highway gears? That's the best way to make a turd. Figure out what is in your engine. Heck, for all we know a cam change and a little head work might make 450 horse. Or maybe it already makes 450 horse, and you just don't see it cause it's got a junk converter.

Learn your car inside and out. THEN you can know where to focus to make the changes you want.