This may sound over simplified, but the cheapest and best thing you can do is spend more time than the next guy making your clearances, (decks, piston to valves, bearings, ring end gaps, etc.) the best you can. Our motors usually make more power and last longer than a lot of peoples who do their own work because we spend the time it takes. No offense to the many on here who do their own stuff, I'm talking about people around my area.
Don't fall into the trick of the week. There are many tried and true methods for the SBC that will keep the cost down when working on a budget. Don't look for HP in the oil system of a bracket motor whatever someone tells you. Build a solid bottom end and look for HP in the top end. How much HP are you looking to make? Are you bracket racing or shootout racing. Shootout racers on a budget are still over my bracket money :wink: :wink: .
There are some really good resources here and do a search on speedtalk.com. Ed Wilson is on both (very knowledgable), Joe Sherman is on speedtalk, and there are others here that have added useful things to many posts. Use the search function over there and you will find a ton of info.
Curtis