Not sure what to do

Nothing is wrong with my current engine, its a bone stock 318 from 1974. i want to get more power without spending too much money. would it be smarter to put better parts on my current engine or swap it out? i assume the engine has over 120k miles, the odometer broke before i bought it.

Would cylinder heads with bigger valves and a performance cam be worth the trouble or should i save my money and buy a short block crate engine? thanks for any thoughts and ideas. i want to have fun with the car but it seems to be a money pit when it comes to making it handle and have power
As long you got a mechanically decent engine no reason not to do the basic tune, 4bbl and mild cam with at least duals, headers better, stall and gears help too. No reason can't get 240-280 hp.

Here's stock low cr 318 long block with 4bbl headers and xe262h cam for 282 hp @ 5000 rpm..

https://www.motortrend.com/articles/mopp-0312-318-long-block-bolt-ons/

Problem is if you want more power then that, question becomes does a 318 make sense or better off with 360 or bigger. It depends and all is debatable and people will for 10 plus pages :)

But to add some parts to an already running engine and gain 50 plus hp is a no brainer to me.