Engine replacement-list of components/sensors to replace

98Bacon said:

I understand that everything CAN be swapped over and I'm all about being thrifty here but.... I'd also like to be smart. For example I was told I should be buying a new a radiator (seems logical), exhaust manifold bolts...? Also it would seem to me that replacing some of sensors that are difficult to get at might be worth replacing before the new motor goes in. Just trying to plan ahead partly because I live in a pretty rural area and would rather order ahead than be driving 30 minutes to the parts store.

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Take a peek inside the radiator. You'll know right away if it's worth blowing money on. If the inside is clean then just blow all the crap out of the fins and stick it back in.

98Bacon said:

I'm going to be pulling the factory 5.7 (315,000mi) from my 98 Silverado and dropping a crate motor in soon. I'm trying to put together a parts list ...
...What are some of of the parts that I should definitely replace vs swap over?

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Updated fuel injectors vs. factory "spider" system
Fresh motor mounts IF YOU CAN FIND GOOD ONES. Good luck, all I saw was thin-steel junk, and polyurethane inserts that didn't fit properly.
Catalytic converter
O2 sensors. They'll never be easier to put the torch to than when the engine is out.
INSPECT THE DISTRIBUTOR GEAR, you can expect to need a fresh one. Possibly the entire distributor. The plastic Vortec distributor is a high-failure item.
INSPECT distributor cap, rotor, plug wires, plugs. Make sure the plug wires are routed properly as shown in the service manual.
INSPECT the flexplate. They're known for cracking.
INSPECT the torsional damper. Maybe the core engine comes with a new one.
Consider a replacement starter motor with heat-shield. Same for the alternator.
Flush the PS fluid, then install a PS filter
Inspect the PCV valve and hoses, air filter element, evaporative fuel canister, fuel filter
When you have the radiator out, be sure the AC condenser and any other fluid-to-air coolers are clean and have straight fins.
If you have an AIR pump on that engine, verify that the pump is good, the plumbing is leak-free, and the diverter valve works.
Depending on your location, install a core-plug engine heater

Supercharged111 said:

20 year old factory sensors are better than new OReilly's ****, so if it isn't throwing a code swap it over.

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The key here is to connect a scan tool BEFORE you disable the original engine. LOOK at the data stream. You'll know if any of the sensors or actuators are screwy. The only sensors I'd replace "just because" are the O2 sensors.

Supercharged111 said:

Take a peek inside the radiator. You'll know right away if it's worth blowing money on. If the inside is clean then just blow all the crap out of the fins and stick it back in.

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There's more to radiator problems than scale in the water tubes. I've seen plenty that have the air fins rotted away from salty road splash. Even if the water tubes are in good condition, if the air fins don't make good contact, the heat transfer won't happen and the engine runs hot. Then there's leaks at the tank-to-core seal.

Much as I hate to suggest a new radiator--because I despise Communist Crap, and pretty-much all radiators are Chinese junk--20 years on a radiator is getting to end-of-service.

Depends, where does he live? Original radiators on my trucks still look good and perform well here in CO. Back home in MI this probably wouldn't be the case.

Schurkey said:

Consider a replacement starter motor with heat-shield. Same for the alternator.

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I wouldn't. If they're working fine, they're working fine. Both are easy to change if they do give problems later.

The key here is to connect a scan tool BEFORE you disable the original engine. LOOK at the data stream. You'll know if any of the sensors or actuators are screwy. The only sensors I'd replace "just because" are the O2 sensors.

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Good idea on scanning the engine now. I might add the oil pressure switch sinply because they do fail, and it's on the back of the engine...although it might be easier to get to on the 350 than on my 454.

There's more to radiator problems than scale in the water tubes. I've seen plenty that have the air fins rotted away from salty road splash. Even if the water tubes are in good condition, if the air fins don't make good contact, the heat transfer won't happen and the engine runs hot. Then there's leaks at the tank-to-core seal.

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I kind of took the advice to be in addition to any external damage. Personally, I have not had fins rot on an aluminum radiator. It seems like maybe I've seen it on copper/brass, so maybe that was on my 69 Buick.

Much as I hate to suggest a new radiator--because I despise Communist Crap, and pretty-much all radiators are Chinese junk--20 years on a radiator is getting to end-of-service.

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I wish mine would last that long.

Excellent , thanks guys. I am building list....

The crate motor comes with a new distributor, flexplate and balancer. I will definitely do the o2 sensors since one is bad anyway. I'm not sure about the AIR pump, I don't believe it has one but I'll look into it.

Since new “bad” parts can complicate troubleshooting on a new install, you may want to install them on the old engine, assuming it runs, and drive for a few weeks to see if they are good or not. Things like temperature sensors, O2 sensors and ignition coils are pretty easy to swap. Fuel pump is tougher to swap, but if you’re going to change it anyway, it doesn’t hurt to make sure it’s putting out good pressure.

For your first swap, I’d recommend making a list as you go in order of disassembly. Then just reverse the order for reassembly. I’ve found by writing the socket/wrench sizes by the steps also saves time during reassembly. Here’s an example of my notes cleaned up. The actual shop notes were pretty messy.

Thanks Iron Possum that is a great resource. Much appreciated!

After doing a swap myself, I would say do the simple cheap stuff and anything thats hard to reach once its in. If its cheap (like spark plugs/wires etc) or sensors in the back, might as well do it now. You also stated exhaust mani bolts. I would HIGHLY reccomend that since your going to have them off anyway. my swap was an LS which came with the mani's but it ended up getting a leak at one point and 2 bolts broke off from rust when trying to remove them. keep in mind the LS is a newer motor but the bolts were still toast.... luckily the aluminum heads allowed me to weld onto the bolts in order to extract them. you wont be so lucky with cast iron. get some new ARP bolts and apply anti seize!!! prolly 50 bucks that will save you a headache down the road.

Radiator will prolly be fine if it isnt leaking and can be swapped in less than an hour if it goes out down the road But get new hoses as those are probably nice and soft by now and are cheap. trust me, getting stranded because of overheating is not cool.... and speaking of cooling, id reccomend a water pump. the front seal on yours is probably on its last leg and will start weaping soon. easier to do while motor is out.

I wouldn’t waste the money. I understand being proactive but there is absolutely no reason to change sensors unless it’s malfunctioning by giving erroneous readings or broken.
Concentrate your expenses in getting good fluids or replace broken things for the vehicle. Say radiator waterpump heater core thermostat all cooling and vacuum lines and hoses if they are originals.
About the only sensor I would replace is the oil pressure sensor if it’s possible n the same spot like a 4.3. If it’s accessible I wouldn’t even do that.

When and if a sensor breaks replace it at that time.