Good concept staying clear of NOS with a stocker. The inventory backside finish may not be in a position to manage it for lengthy. These are some of the fundamental bolt-ons I do while I construct a slight road engine. Depending at the yr of the 350 (distinct years had distinct heads, distinct compression ratios, distinct valves, and many others.), there may be plenty you'll do with out a whole rebuild. Pre 'seventy four Chevy ram horn manifolds produce well horsepower on a slight road engine, so if the engine is a 'seventy three or prior (which might be an unlawful change in a few states), and except you are watching to get into the four hundred+ horsepower variety, you'll use the inventory manifolds and move with a twin cat/twin exhaust process. Don’t move precise-duals, because the Chevy is a 60-measure block and your torque curve will undergo. Use a crossover or X pipe within the exhaust to get a well steadiness for your horsepower and torque curve with none spikes. Since you did not specify the raise/length/overlap of the cam, I can not let you know what RPM variety to shoot for. I'll anticipate it is not too radical, otherwise you might be asking why the engine is slower than the 305 used to be, so I’ll move with a 6,000 RPM redline. The Wieand Action Plus Manifold is a well alternative for throughout torque and horsepower. The Edelbrock and Holly are well too, however the Wieand will deliver you a bit of extra torque within the mid variety, whatever the Chevy engine demands. If you could have the inventory Quadrajet Carb, except you understand how to rebuild it and recognise the tips to enhancing them (there’s plenty), I'd suggest switching to a Street Avenger Carburetor. You'll get bigger airflow with out the low or mid variety WOT lavatory a non-transformed Q Jet could have. High float heads are an effortless bolt on for gigantic energy, however they are costly. Porting and sharpening the heads, and getting a 3 attitude valve process to your present heads will support, but when they are low C.C. economic system heads, and feature smog bumps within the exhaust ports, do not anticipate an excessive amount of from them. If the 350 has an HEI ignition, they're very well for efficiency if transformed accurately. Stock, it can not manage a top RPM variety, so adjust it with a top efficiency coil and module, and change the inventory vacuum develop with an adjustable one. Re-curve the ignition to suit your RPM variety. If you spot crimson filth at any place within the distributor cap, you'll be able to have got to rebuild the distributor and change the bushings (a usual predicament with the HEI). It's less difficult to exchange it with an entire hello-po process, however fees extra. Use a top float air cleanser if you'll duct contemporary air into the engine from a cover induction form hood scoop. Without a scoop, use a closed process and duct contemporary air in from beneath the bumper or subsequent to the radiator. It's tight, however there may be room to try this on an eighty three El Camino. The open detail air cleaners seem cool, they usually paintings bigger than so much inventory items, however the air beneath your hood is scorching from the engine, and also you have got to get cool, contemporary air from someplace as opposed to beneath the hood. Whatever you employ, continuously use a top float filter out, like a K&N unit. If you are utilizing the 'eighty three TH seven-hundred R4 trans, it demands a few paintings because there may be an electrical override at the torque converter for fuel mileage, which kills the torque at broad open throttle while you procedure five,500 RPMs. You can get an digital close-off package to repair this. Also, placed a well shift package in, recalibrate the governor, and change the inventory vacuum module with an adjustable one. Rear axle ratio is anther problem. Again, to fulfill fuel mileage standards in eighty three, so much El Caminos ran a top rear finish ratio. A new ring and pinion set round three:ninety will support your e.t. Don't move four:eleven or four:fifty six for those who plan on riding any farther than 1 / 4 mile at a time. This will all paintings with a inventory backside finish, so long as the engine's in well situation to begin with. If you wish to get critical, you'll continuously move with a .30 over bore and a solid four hundred cid crank. The influence will probably be a 383 cid, and you'll with ease construct 450+ horsepower into it with out NOS. Staying with a inventory backside finish, have the forged iron crank polished and balanced. This is well for another 15 to twenty horsepower at the 350 Chevy, and a smoother torque curve on the grounds that the inventory Chevy crank is to this point out of steadiness from the manufacturing facility it pulls the engine down dramatically. These are some of the fundamentals. You can do plenty extra relying on how so much energy you wish, and the way quick you wish to head. Check out the car phase at buddyandoscars. They have a efficiency phase with the entire bolt ons you'll be able to have got to get a few well energy from your El Camino.