Beautiful car in a beautiful color combination!
ONE thing people who have stroker motors never mention is MPG. They usually mention "size" but not what it takes to "feed it". Most are not "distance cruisers" for that reason, I suspect. And that was before gas prices got to where they have been for the past decade or so. BTAIM
With a car that looks that good, a mere 383 4bbl will be fine. You DON'T have to prove anything with a big motor as the car will get enough positive attention without anybody knowing what's under the hood. 2bbl carbs, too, are fine. Only costing "power" above 3000rpm. Guess where the bulk of your driving is, under 3000rpm. The primaries of a 600cfm carb are the same size as the throttle bores of your existing 2bbl carb.
To me, the bulk of the performance of modern V-8s is due to the fact they are always in front of an 8-speed automatic, which has a very deep low gear ratio, for "great launch" (as the factory guys term it) off-idle. Once underway, the 3rd gear and above keep the engine in s particular power band that is usually narrower then what it was on the older engines. So faster acceleration with the top 3 gears being overdrives, which is why they get the fuel economy they do on the highway.
The car should already have the 3.23 rear axle ratio in it, which can help things a bit without hurting fuel economy too much on the highway. 1970 383 2bbls already have the cam as the 383 4bbls anyway. So just need a good dual exhaust under it, basically.
Easy upgrade would be an Edelbrock Performer intake with a 625cfm Edelbrock AVS2 carb. A better venturi design than what would have been on the car to start with and a 4bbl intake that is as good as the OEM Chrysler 4bbl intakes, if not a few horsepower better. An electronic ignition, if not already there, can round things out.
An easy stroker upgrade would be to use a rotating assy with a 3.75" stroke (same as the 440) that should make about 450cid. That should yield more lower rpm torque than any similar 383 might build. Some might argue that you might as well and "go big", but at what additional cost? NOT just in engine build costs, but also in related chassis upgrades to be able to use that additional power of the 500cid V-8. No sense in paying for it if you're not going to use it! This gets into NOT ONLY tires, but brakes and rear suspension, too.
Remember, too, you've got a convertible body which is not nearly as structurally stiff as the normal sedans most of the strokers find themselves in. "Torque Twist" is the enemy! LOTS of little side issues!
In the mean time, learn about the car and what made it better than similar GM cars. Make sure that somebody tunes it that will tune it to stock specs and ensure it is running as good as it can. Even to lay a bit of rubber, if desired. The allegedly-popular giant smoky burnouts or similar are NOT a part of that car's heritage, although some can do that if the driver know what they are doing.
Because the car is as good looking as it is, you don't need to impress ANYBODY with a huge motor under the hood. Be a good steward of the car while you own it. Which means keeping it as stock and good looking as you can. Certainly, a few things can be changed, but too many of them detract from things, by observation.
Enjoy!
CBODY67
