Fred, I work in a speed shop where we also have a complete engine machine shop. We've built everything from early Hemis for airport tugs to 800 cid IHRA Pro Stock motors.
Here are some facts you need to remember -
1984 SBC. Light block (less material in the block casting) that is 23 years old. If it has not already been rebuilt, it is really going to need it. And if it has been "rebuilt", how was it accomplished? I know fellows that think running a ball hone in the cylinders and putting in a fresh ring set and new bearings is how to rebuild a short block.
The truth is, you need to see how much taper you have in the cylinders. Measure a cylinder at the top and again at the bottom, to see what the taper is like. If there is enough taper, the cylinder ends up like a funnel and the rings almost immediately lose radial tension, as they are expanding and contracting with each pass through the cylinder. If the block needs bored and finish-honed, that's a new piston set and you are going to balance that rotating assembly, aren't you?
Are the main webs round and straight? If not, there's an align hone job in your future.
Those cylinder heads are also light castings and will definitely need milled to get them flat. Not to mention the valve job, and the likelihood of bronze guide liners to get guide clearances back where they belong. And that is assuming the heads are not already cracked from 23 years worth of heat-cycling.
Rods that are 23 years old? No questions asked, they need re-sized and fresh bolts. Don't give it a single thought, just do it.
As you can see, you're starting to run up quite a tab.
I see people, every day, wanting 4 bolt main blocks forged pistons and 300 camshafts for motors that will never see 6500 RPM. Waste of money. Sort out where you want the motor to spend most of its time and build things to make the motor happy in that RPM range.
If you never plan to rev the motor over 6000 RPM, a two bolt block and a cast crank will work just fine. All you need to be concerned about is making sure the cylinder walls are straight, bearing clearances are spot on and you'll have a worry-free short block.
I just read something (can't recall where) about the prices of aftermarket parts. And that's something to look into, because some of the crank and rod prices are really good. But be careful. There is a very popular crank/rod/rotating assembly supplier that supplies some questionable pieces. Sure their cranks are low dollar, but we rarely ever get to wash one and bolt it in. Because the journals are not round. Suddenly that inexpensive crank just got ~$100 higher, because it needs to be ground.
There's no question, you can ball-hone a block and put in a fresh ring and go. But if that ring is worn out in the first 1,000 miles, what favor did you really do yourself?
Frankly, a 23 year-old 350 is not much more than a core. And even if it does run, it's questionable history makes it a $300-$400 core, tops. If somebody wants $650 for a running motor, ask them to bring it up to operating temperature and then perform a leak-down test on it. Not a compression test, but a leak-down. That way you will be able to see how "leaky" the motor is and be able to hear where the air is going.
I'm the lazy sort. Once I get a motor laid in the frame, I don't want to be pulling it back out a year later.
