ok im going to a school called wyotech n pa and im taking a high performance class but all the teacher are ricers and the chevy teacher isnt ever there so im building a 73 350 for my car and have absolutely no money to make a 600hp beast so what r some good things to keep and what are some good things to replace all i need is a motor with mild performance and durability what kinda cheap upgrades can i invest in to get what i want  

Well, if you have no money then 600 horsepower probably isn't attainable!

Do you mean what stock parts do you replace? If that is the question, almost everything! Most notably the cylinder heads, intake manifold, exhaust manifold (for headers), carburetor, camshaft, entire valvetrain!. You can try all of this on a stock buttom end but more than likely the compression will be awfully low and limit your midrange and buttom end power with a large aftermarket cam. Also, if you intend on making 500-600 horsepower the stock components of the buttom will be pushed to their limits.  

thats not what i asked but ok im not lookin to make a 500hp motor all i want is like 300hp  

Well, it surely isn't easy to decipher what you're asking!

Please make it clear for me! Are you asking what aftermarket parks are you going to need? Which are worn? Which stock pieces need to be replaced? What are you doing here?  

im rebuilding a completely stock motor 73 monte carlo what hard parts are a good idea to change and which ones are good to keep like the crank, pistons rods, cam, push rods, rockers valves and springs which could i keep and which should i just change to save me the hassle of having to tear it back down it a part fails all i want is a reliable motor till i get the money for the performance  

Well, if you're going to rebuild this engine completely stock then it's unlikely a stock part will fail unless it has a lot of time on it...

If you plan on adding aftermarket pieces later on strengthening the rotating assembly now is a good idea. Usually aftermarket hypereutectic pistons are the first thing to use because they're cheap and the ring lands in the stock cast pistons are probably shot, along with possibly the wristpin bore. Significant doses of nitrous or rpm's around or over 7000 would probably require forged pistons.

In some cases the stock connecting rods may need re-sized, especially if you decide to use fresh rod bolts, which is a good idea. Budget aftermarket connecting rods (namely Scat & Eagle) sometimes aren't much more expensive than rebuilding the stock pieces and offer some increases in strength over stock. Aftermarket rods also offer the use of floating wristpins much cheaper than attempting this with stock rods. But fresh stock connecting rods surely can handle 300, 350, or maybe even up to 400 horsepower.

The factory crankshaft will most likely need to be turned. If it is heavily worn an aftermarket cast-steel crank can be a viable option for a little extra dough. Steel is usually a better crankshaft material for high rpm engines but if the power is kept reasonable (maybe 400 maximum) iron cranks can be beneficial in terms of long-term durability. There weren't many factory forged steel cranks in 350's so they aren't easy to find. An aftermarket forged steel crank (usually a 4340 alloy) offer significant increases in strength over cast-iron or cast-steel cranks. Look for these pieces when horsepower is getting really high, like 550-650.

The camshaft without a doubt should be changed. Newer grinds offer significant gains in power without costing very much (especially if staying with a flat tappet). Just remember to do everything in your power to have a smooth break-in forthe new cam and lifters to make sure they live for a long period of time.

If the camshaft is to be upgraded significantly the pushrods will need to be changed as well as aftermarket pieces are much stiffer and do a much better job of 'working' the valvetrain at high rpm. It's common for the stock pieces to fail when running an engine hard at 5500-6000 rpm, even with power production along stock levels.

Factory stamped steel rocker arms usually have poor tolerances (differing rocker ratios from rocker to rocker) and wear easily where they actuate the valve. This can cause the valve stems to mushroom as they are hit by a blunt end of a stamped steel rocker. I usually recommend a Comp Magnum roller-tip style rocker arm for warmed-over rebuilds. Aluminum full roller rockers are the next step up for high performance builds but the aluminum is bound to fail at sometime in their lives (even though it may take some time). The aluminum rockers reduce friction slightly and are basically required for good valvetrain operation above 6500 rpm.

The factory valve springs are 9 times out of 10 shot because of the fatigue they receive by even sitting for 10, 20, or even 30 years. They also don't provide enough spring pressure to control the quicker moving valvetrains provided by newer and faster aftermarket camshafts. Stock valve springs are also known to break even when running a stock engine hard, so changing them is definitely required. Usually most rebuilders count on the camshaft companies to recommend a valve spring that matches their particular camshaft, which I recommend going this route as well.

More than likely the factory valve stems and tips are worn and need replacing. This can also be beneficial to a performance engine because you can replace them with a stainless steel valve (more durable material with hardened seats) and can also reduce weight to make valvetrain control easier at high rpm.

If the valve stems are worn, more than likely the valve guides are worn as well and require replacing. Performance engines will like a bronze alloy guide more than an iron one in most cases as the added valve speed can cause wear between the two hard metals (so a soft metal is used instead). This also has the benefit of using a very tight clearance between the valve and guide to help improve valve control at high speeds (makes the valvetrain's job a little easier).

The factory valve seats may be able to stay (especially if they're post '75 heads) but obviously they will need to be re-cut for your new valves. This is also a place to gain significant amounts of power because the stock valve jobs aren't meant for performance (awfully wide seats) and then the port's bowl & throat can be blended into the new valve job to drastically improve flow. If you deem it necessary this is also the time to increase the valve sizes of the engine, which also adds horsepower potential by improved breathing.

This sounds like I'm trying to write a short story, so, I suggest taking a look at a couple of books. They will give more detail on dealing with each part of rebuilding a Gen I small block Chevy.
"John Lingenfelter on Modifying Small Block Chevry Engines"
"How to Rebuild your Small Block Chevy" - by David Vizard
"How to Build Max Performance Chevy Small Blocks on a Budget" - by David Vizard  

ok thanks  

Feel free to ask any more questions that you may have. There's a big block of text there that I want to know whether or not you absorbed it.  

yea i got that but i do have another question it involves a buick regal t type i know a guy who has one and i have a feeling that he got ripped off i dont kno if you know much about them but anyway it has a 307 in it and i only thought that they offered the 4.1 v6 and the turbo 3.8 did they have a v8 option for the t type i didnt find any thing out about it if you dont know thats fine  

As far as I know, no T-Type Regal came with the 307, they all had the 3.8L turbo V-6. Sounds like your buddy got hosed.

Good lick on your engine build. Properly built on a budget, your stock-type rebuild should be capable of making 350 HP.