I understand your pain with not much under the loud pedal!
I've got an 81 with the anemic 190 hp L81.
Just FYI, if would go 383 you'd gain a lot of torque and the hp gain would depend on how radical you go with the cam. Even a moderate
cam on a 383 will get you close to or easily well over 400 hp, BUT you'd need a little more $ on heads, intake and exhaust to get effective power that's available with those extra cubes.
Here are some awesome 383 examples
Ryan's Stroker Combo Page (9-16) Look at combo 15. Awesome motor, but the AFR heads aren't cheap. And you can scroll forward and back to other pages, Look for combo's with Vortec heads, also pretty stout and using less expensive Vortec heads.
This one would make an awesome street combination with less expensive Vortec style heads and a moderate cam.
HT 383 Crate Engine Test - Tech Article - Chevy High Performance Magazine
HT 383 Small-Block Chevy Engine Buildup - Tech Article - Chevy High Performance Magazine
And again just FYI, here's my real tight budget setup that will end up with at or close to 325 hp peaking at a moderate 4500 to 5000 rpm (I don't want to destroy my shortblock and can't afford to do anything to it like changing pistons, and would like to avoid the work of R&R the engine & basically rebuilding it) and around 400 peak torque at between 3000 to 3500 rpm. And I need to retain decent gas mileage for trips I plan on taking when I retire.
Leaving the stock shortblock alone except for cam, there are a couple other major items that will increase power. Heads is 1 big one. Having done lots of research, I'm currently thinking of EQ Vortec heads which can be had with basic valve parts (comparable to oem Chevy Vortec heads) for about $650 a pair.
EQ Cylinder Heads @ Rogers Performance
EQ heads reportedly have better exhaust flow, somewhat of a weakness on oem Chevy Vortecs, and have a sturdier design so they avoid the potential for exhaust valve seat cracking in the oem Vortecs. The Vortec is an excellent intake port and comb chamber design which makes good power with excellent low rpm torque for a good warmed up street engine, and those heads are known for a good
budget power upgrade.
A step up from there are the EQ heads with stainless valves and bronze valve guides and pc seals for about $875 from Shaver Specialty. Maybe a dab more power from a little better flow cuz of the SS valves.
Here's an engine build Popular HOt Rodding did with those heads on a 350 motor on a real budget. Bigger cam than I'd want to run on
the street mostly for mileage considerations, but lots of good info to think about.
Vortec Small Block 350 Chevy Engine Build - Popular Hot Rodding Magazine
The next step would be the excellent RHS or Dart Vortec iron heads for a dab over $1,000 which would probly give an easy extra 25hp or more over the EQ heads, depending on which ones you'd use and your cam. Everything needs to match regarding rpm range to get the most out of your parts, and you would overmatch the Performer intake if you go too big on heads and cam. Scroll down a ways to the Pro Torker section in the below link and read the info. Available at Summit Racing and other places. Good non-Vortecs can range from Edelbrock to the more expensive Trick Flow or AFR.
RHS - Cylinder Head Flowcharts
The EQ's will support over 400 hp with the correct supporting pieces, and give excellent low rpm torque because of small intake ports that maintain good flow velocity at low rpm, important to good gas mileage on the highway.
Carb style manifolds that fit under the stock hood are limited to the Performer type intakes that make excellent low and mid range power and are effective up to about 5500 rpm, plenty rpm for power but not so much you're going to hurt your stock engine. And those intakes are inexpensive, around a little over $100. There are several brands in that same style.
For cams, it's cheaper by far to stay hydraulic flat tappet than to convert our older blocks to retro roller cams, and in the milder lineup
of cam specs Comp Cam's Camquest dyno program doesn't show any advantage to roller cams, surprisingly. I will end up with either the
Comp XE249-H or SE256H-12 which are milder than I would have at first thought I'd use, which will result in the hp and torque figures, above. Other good ones for a little more power, alto at higher rpm torque and hp peaks but still very streetable, are the 262 or 268 cams in the same XE series.
I'm going to use a 2bbl 670cfm throttle body Holley Pro Jection efi setup I've already got, adding a closed loop kit to it so it runs at the
correct air fuel ratio automatically at steady engine speeds i.e. on the highway. It will support up to about 325 hp with increasing the pressure via adjusting the regulator up a little.
If I was going to buy something in efi, it would be something like the FAST EZ efi which is a self tuning setup, or the newer Holley throttle body setup, both of which work with an unmodified Performer type intake and give plenty power with good mileage and are easy to install and tune. But they're not inexpensive. Holley is a little over $1000 and the FAST is over $2000. If you stay carb you'll get the same power but a little less driveability and less mileage, however lots cheaper. Great street carbs are the Edelbrock's which give good throttle response at low and moderate rpms along with good mileage. Altho Holley's in the 650 size are also good and easy to tune. Both those carbs are usually set up (jets etc) real close for a typical 350 size street motor right out of the box. Another excellent carb, altho a dab more expensive is the Holley style Demon carbs by Barry Grant
Demon Selection Guide
I think your money would be better spent doing something like the above rather than the 383 stroker - you could always go slightly larger heads and cam on your stock shortblock to get an easy 350 to 375 hp and still get a very streetable engine with good mileage. Using our stock shortblock and the low compression pistons, you're going to need to go to 91 octane to avoid detonation, BUT that will allow you to use more advanced timing and go to a higher 9-1 compression ratio which will give about enuf extra gas mileage to make up the cost.
You'd also have to use 91 to get cost effective benefits out of a 383.
Just FYI, also, I'm going to replace my 2.87 gears with 3.31's and swap my 3 speed auto out for a mildly built 200-4R and 2200 converter from Bowtie Overdrives for a reasonable cost. But you probly already have a 700-R4 with a low 1st gear and OD? If you add much power to your engine, you can shorten the life of that trans in stock form as there are some pretty well known weak points that can fail with very expensive consequences. Check out
Bowtie Overdrives for a good inexpensive upgrade that fixes those problems.
Good luck!