Personally I wouldn't worry about stroking it unless you are planning on building a drag car. I rebuilt the 383 in my RR this year and it pulls hard! I used KB400 pistons with 440 Source Stealth heads, Lunati Voodoo cam with a Torker intake and Holley 830. I also put in a TCI 3000 converter and 3.91 gears. Very fun street car. Runs on pump gas, very dependable, brings a grin to my face every time I stomp on the GO pedal!
Though the OP hasn't said what his plans/use of his car is, your method certainly does work, but is far less than ideal with the parts available today.
I love "old school", but lets break this down.
KB400 pistons. --- About $350.00 bucks, and Hyperutectic instead of forged, plus they are domed, which is an impediment to flame travel. Much worse is the fact that they use the ancient 5/64th's rings which increase friction and bore wear. --- I personally love hyper pistons for the street, but I only use the Speed Pro units with 1/16" rings, no huge top ring gap, and much better ring selections. I personally won't use Hypers for a performance build as they won't tolerate detonation very well, and your build is certainly high performance.
440 source stealth heads. --- About $1050.00 w/shipping. Great heads, but the larger valves are not conducive to low RPM torque. Still need "going through at additional cost" (as does any part), and unless you are running a solid lifter, with upgraded (cam killing) springs, at 7000+ RPM; will never outperform stock heads on a 383. Just a matter of physics, not opinion.
Lunati cams work well, but require 3 bolt cam drive "chain/gear" sets at additional cost. Fine for the heavy spring, 7500 RPM engine, but a waste of money on a street/strip car.
Torker intake. --- A super torque killer on a 383. not a bad manifold, but definitely not ideal compared to newer designs, or even the old street dominator.
I have never used a Holley 830, so I can't comment on it.
TCI "3000 RPM" converter, and 3.91 gears. --- I'm just guessing, but I bet the cost of upgrading to both these is at least $700.00 to 850.00+. Certainly necessary for your build, but totally unnecessary for a high torque, long stroke, engine. And if you get 8 to 9 MPG, I would be surprised.
Then you have the cost of balancing, rings, bearings, machining of the crank/rods, etc; that adds a few hundred $ on top.
Now lets look at a "49x stroker kit for the 383 block.
Forged pistons w "1/16 rings, good molly rings included. 4340 steel crank with full radius filets for much higher strength. 4340 rods w/ARP bolts and full floating pins. Bearings and balancing included, etc.
You gain 200+- Ft. Lbs. of torque with the stock converter and gears. At least the same amount of HP at a much, much lower RPM. Ability to use a less radical cam w/stock heads, and 14+ MPG.
Since block machining and parts checking is the same for either approach to a build, lets assume that it's a wash.
The high RPM 383 will run you about $700.00 more (at minimum) to the far more powerful, and tractable/streetable "49x engine. Plus with the stroked 383, you can still drive it on vacation at highway speeds. Something that can not be done with the "high strung" 383.
The facts show that there is NO good reason to do the 383 instead of the stroker. With the stroker, you will save money, have a much more powerful car that is street drivable, substantially more fuel efficient, and have a much longer life span. ---- At a much reduced cost.
I applaud your "old school" approach to your build, but it is definitely not the best or cheapest way to go nowadays.
