I recently acquired a stock 1979 350 to put in my 65 El Camino. I know that the engine is only rated at 170 hp, which is pretty low. I don't need a high horsepower engine, but a little better than 170 would be nice. I am not familiar with what made these engines so low on horsepower compared to earlier engines and that is why I am asking these questions. All the smog equipment will being coming off the engine and would like to know if there are any simple and inexpensive changes that will give it a little more pep. I am thinking of things like cam timing or a whole new cam if it would drastically change performance. I have no plans to take the heads off the engine and I don't want to rebuild it, so simple things would be best. It will have a Qjet on a stock manifold (unless an aftermarket manifold would make a big difference). Any input would be appreciated.

The compression ratio's were lowered post 1970.
What was a 9.0:1 cr with the 350/2bbl (250hp) and the 10.25:1 cr with the 350/4bbl (300hp) in 1970 became an 8.5:1 cr 350/2bbl (165hp) and 350/4bbl (175hp).
Main differences were the combustion chamber size and the cam.
Swap heads and change cams and you could have 300-350hp.
Another thing to keep in mind with the HP ratings is that they changed from gross to net so there not really a direct comparison.

My 1974 Camaro theoretically had that 8.5 ratio. Once everything was checked, turns out it was actually in the high 7s.

Flat-top pistons, a little decking, and a .450 to .470 lift cam will make a big difference.

A better set of heads will wake it up quite a bit if done on top of that.

To get a little more specific, my car at 3800 pounds with me in it ran mid-15s with a 268H cam (218* at .050, .454 lift), flat-tops (which only brought it up a little better than the originally-claimed 8.5), performer manifold, and a 600 CFM carb, with a 2200 RPM converter and a cheap set of headers. It was a lot of fun on the street, until I started turning it into a full-time race car. This was still with 2.73 gears and the original heads, I think they were 882s.