Hi guys,
I need your experienced advice. Im 70 yrs young and havent done any hot rodding since my SBC days 50 yrs ago. I need advice on how to get 400-450 HP from my stock 340-6BBL AAR Cuda. I want to keep the 6 barrel and keep the stock look. I am not opposed to finding a 360 if that is absolutely neccesarry. Thanks so much for your valued input and helping me.

Option 1 150 shot of nitrous added to your current setup.

Option 2 Stroke the 340.

Option 3 Cam and heads on your current engine

What I would do if I had an original numbers matching AAR- pull the numbers motor and trans, set them aside and build a 360 or stroker (depending on budget) and trans to play with.

X2

I agree with what was said above. Assuming you have a matching number AAR 340, I would keep it stock. Pull the motor and go with a built 360. The HP you want should not be too hard to make.

Are you opposed to aluminum heads painted the factory color? If not ported heads will work. That with a decent cam, it would easily do it in a 360. Add on? Stroker crank would even be better. Headers would help as well but may not fit the look you want. I have a 360 4 speed in my Challenger. Except for headers, valve covers, and air cleaner it looks stock. It runs easy high 12s with a 3.55 gear and sticky radials. Ported 360 heads, 220@.050 hyd roller, 9.0-1 compression. It runs fine on 87 octane.
Doug

5.9 Magnum block with a 4" crank and then the AAR top end put on it. Install a decent roller cam and it would be a fun little engine. Only visual drawback is no mechanical fuel pump on the 5.9 block if your trying to keep it close to original looking. If that is the case then an LA block would be better suited. Forged pistons and better rods + ARP bolts would help ensure it stays together as piston speed increases with the longer stroke.

4" crank would boost the low and mid range torque up and get the car moving easier, which is ideal on the street.

You could still run the exhaust manifolds, but it would be good to make the rest of the exhaust as free flowing as possible.

I think the simple way is a set of Trick Flow heads, a bigger cam, and a high flowing exhaust. That should put you in your target range without the worry of nitrous. You can paint the heads to keep the stock look.