Any time you do a major drivetrain overhaul you’ll be left with a lot of leftover parts. Whether it’s just an engine or an entire drivetrain it takes up space and you might be tempted to get rid of it. A lot of people are tempted to take it to the junkyard or sell it online. The problem with that is that there are a lot of small parts still attached you’ll need to re-use. Save everything until your project is done and your ride is running before you get rid of anything.
If you have a higher-mileage ride or blown engine you want to refresh it with a re-manufactured engine of the same type. And when you order one, you only get the basics: engine block, cylinder heads, oil pan, valve covers, and a balancer. Every accessory needed to run the engine isn’t included.
When installing a long block there are several pieces you’ll need to re-use. Take the accessory drive for example. You have the air conditioning pump, alternator, water pump, power steering pump plus the tensioners, idlers, and all the small brackets needed to align everything. You also have the starter, exhaust manifold, intake manifold, fuel injection intake system and all the sensors. Plus you have the flex plate out back, the distributor, etc.
There are also things when it comes to wiring you want to hang on to. Like power distribution, air conditioning and the wires that run the gauges up to the instrument cluster.