Upgrades for longevity

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

izzylopez

Newbie
Joined
Feb 6, 2024
Messages
2
Reaction score
2
Location
Chester, CA
New to the site. Just picked up my first OBS few months back. 1998 K1500 5.7L. 167,*** miles. I'm wondering what parts to upgrade for motor longevity. I don't care too much about performance, but if a part is more durable than stock but also produces more power in any way, I'll take it. I want to know what aftermarket parts to buy especially when any engine component fails. If there's a better aftermarket part, I want it. My hope is to keep this truck running for my lifetime.

If there are other threads with my specific question, feel free to link them. I'm interested and excited to hear and learn from all of you guys, old and young! I don't know anyone who can teach or show me stuff so videos are very helpful as well. I'm 22 and dabbling in engine work but my main focus is maintaining, but upgrading along the way.
 

Sean Buick 76

I'm Awesome
Joined
Jan 6, 2024
Messages
888
Reaction score
1,876
Location
Edmonton Alberta
My best advice is to do frequent oil changes! Some people prefer to use conventional oil and quicker changes while others prefer synthetic and longer change intervals. Either way the key is to keep clean oil in the engine and never let it get too dirty or low.

Depending on the previous owners oil change habits and the mileage you may need to do some flushing to clean the engine before starting your oil change schedule. I add some trans fluid to the oil 100 miles before each oil change when trying to clean up an engine. The trans fluid is high in detergents and will help clean things up.

Next would be spark plugs and wires, they should be changed every 50,000 or so.

If there are any check engine light codes then promptly diagnose and correct and it will live a long happy life…

Oh and avoid lugging the emgine below 1700 rpm it will cause detonation.
 

Komet

I'm Awesome
Joined
Nov 12, 2022
Messages
669
Reaction score
1,697
Location
Skagit Valley, WA
Upgrading is a common misconception. The aftermarket is filled with garbage and the more things you change, the worse your vehicle gets unless you're redesigning how the entire system works. Even then you won't be enhancing reliability, at best maintaining it. If you're serious about keeping it forever, download the factory service manual and start by changing all the fluids. Then, do all the other tuneup and maintenance jobs as needed replacing parts with OEM quality or otherwise the highest quality available. If you're a weekend warrior, that'll take you a year and then you can reevaluate how serious you want to get. More serious is more cubic dollars and double it for the tools you'll need.
 

NMNorsse

OBS Enthusiast
Joined
Jan 25, 2023
Messages
58
Reaction score
59
Location
Albuquerque
I'd start off by "baselining" the truck. Go over whatever records you have and start checking and repairing everything. Start with safety items.

Eg. Brakes. How much pad/shoe is left. How much rotor or drum is there. When was the fluid last changed? How old are the brake lines/cables and what condition are they in?

Suspension. How are the shocks and springs.

etc...

When everything is up to ***** and all the fluids are new or you know when they were last changed, you know when everything is due for more maintenance.
 
Last edited:

RichLo

E I E I O
Joined
Jan 6, 2015
Messages
3,645
Reaction score
5,631
Location
Wisconsin
Yep agreed with all above, these trucks are pretty stout from the factory and usually factory parts are better than the replacements that you'll be replacing them with. Keep up on general maintenance and replace parts only as needed then get top quality parts like AC Delco, BOSCH, etc.

The only known weakness's in the 1500 models are the 4L60e trans starts slipping between 150k - 200k so that might be needed in your near future if it hasn't been rebuilt already. Start saving for that and find a reputable trans shop that is trusted in your community, or swap in a 4l80e. Another known weakness is the 8.5" rear-end. That can be upgraded to a 9.5" from a 6-lug 2500 model. Keep your eyes out for one of those with matching gear ratio as your front diff to swap in at your leisure rather than scrambling to find one when something goes wrong with your unit.
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
11,144
Reaction score
14,047
Location
The Seasonally Frozen Wastelands
1998 K1500 5.7L. 167,*** miles. I'm wondering what parts to upgrade for motor longevity.
Engine longevity should be a distant second priority. FIRST priority is to verify that the vehicle is SAFE to drive--steering, suspension, brakes all functioning properly. If the engine fails, you're late for work. If the vehicle doesn't stop, or stay controllable, you maybe kill someone.

Having said that, the ABSOLUTE BEST THINGS you can do to assure engine longevity are:
1. Get several oil-sample kits. Send off an oil sample for lab analysis NOW. If the report suggests problems, fix whatever is needed. Send another after the oil has ~6 months/6000 miles on it. You may find that once-a-year oil changes are perfectly acceptable, and maybe you don't even need to change that frequently. My Trailblazer gets the filter changed at 13,000, oil level topped-off, and I don't change oil until ~26,000 miles--and the oil analysis still says the oil is "fit for further use". But that can change if the thermostat fails, or an injector leaks, or you have some other engine-related failure like leaking intake gaskets. Does oil analysis really work for extending oil-change intervals? I don't really know. That Trailblazer only has 21 years and 280K miles on it with nothing more than replacing the ignition coils and spark plugs, so I don't really know how this is going to work-out long-term.

2. Maintain all the usual "tune-up" items in good condition. Cap, rotor, plug wires, plugs, EGR system, PCV system, spark advance, knock sensor system...you get the idea. Vortec engines are susceptible to distributor cap and intake gasket problems. The poppet-style injector spiders are known for failure, generally replaced with electronic injector spiders. O2 sensors, and MAF sensors have an expected service life, they deteriorate in use. An O2 sensor, for example, is questionable after 50K miles, even if it seems to be OK. All the other sensors are good until they aren't. You should probably replace ALL the O2 sensors soon.

3. Buy an aftermarket, bypass oil filter system. Plumb it into the engine oiling system. I get mine used, or NOS from eBay. Amsoil sells "new" ones, as do several other manufacturers. The kind I get--the old SKY-brand "Frantz" toilet-paper filters use a roll of cheap assrag to keep the oil cleaner than new. Filters-out particles as small as what's in cigarette smoke. As long as the filter housing is hot when the engine is fully-warm, it's doing it's job. When the filter housing doesn't get hot any more, the filter is plugged and should be replaced. Often takes years to plug a filter, depending on mileage and driving conditions. The oil, cleaned with the regular filter AND the bypass filter, is good as long as the additive package isn't worn-out--which you learn via the oil-sampling/analysis.

Upgrading is a common misconception. The aftermarket is filled with garbage
Amen!

download the factory service manual and start by changing all the fluids.
...and filters. Consider installing a PS filter. Synthetic fluids are generally preferable to "dinosaur" oils/greases; but better CLEAN, cheap fluids than dirty expensive fluids. MOST "synthetic" oils are not synthetic at all--they're based on plain ol' crude oil, that's been "processed" by having Van Halen played at it at extreme volume levels until it submits. REAL synthetic oil is fairly rare.

Especially important is to flush the brake fluid INCLUDING within the ABS unit, which will require a scan tool.

The service manual set can be downloaded from links posted in the Sticky section of this forum.

Then, do all the other tuneup and maintenance jobs as needed replacing parts with OEM quality or otherwise the highest quality available.
On a "new-to-me" vehicle, I do an actual inspection of everything I can think of. "As needed" is otherwise determined by when the vehicle fails to get me to where I'm going, or fails to get me home. Better to actively inspect than to find out "the hard way".

But you're right about using quality parts especially for critical systems.

The only known weakness's in the 1500 models are the 4L60e trans starts slipping between 150k - 200k so that might be needed in your near future if it hasn't been rebuilt already. Start saving for that and find a reputable trans shop that is trusted in your community, or swap in a 4l80e.
Yup, the 700/4L60/'60E are weak. Not the only weaknesses, though.

Another known weakness is the 8.5" rear-end. That can be upgraded to a 9.5" from a 6-lug 2500 model.
K2500 6-lug as a donor for a K1500, C2500 6-lug as a donor for a C1500. The C1500s have the additional complication of being a 5-lug axle shaft/wheel while the C2500s have six lugs.

Keep your eyes out for one of those with matching gear ratio as your front diff to swap in at your leisure rather than scrambling to find one when something goes wrong with your unit.
Amen. You'd also be upgrading the rear brakes at the same time, which is HUGELY worthwhile. The original C/K1500 254mm Leading/Trailing shoe rear drums are pathetic. They're perpetually out-of-adjustment leading to a low brake pedal. Keeping them adjusted means using the park brake frequently, and nobody does that so the park brake cables seize.
 
Last edited:

sneakingfart

OBS Enthusiast
Joined
May 6, 2023
Messages
57
Reaction score
45
Location
NY
I will generally echo the others here. That said, outside of fluid and filter changes, I really don't see the need to go beyond by adding additional filters, pre-filters, etc. These engines are solid and known for well over 200k trouble free miles. It's all the other stuff that tends to go bad. AC components, power locks, switches, fuel pump, wheel bearings, etc. All minor things on their own, but definitely add up. I also disagree that the 4L60e trans and the 8.5 inch rear end are weak. They are fine for the application. If you're going to do heavy towing, run oversize tires, abuse off road, etc, then sure. 200k miles for a well cared for 4L60e is also not uncommon.

That said, if you're looking for reliability (not being left on the side of the road), there are a few things.

Change your coolant, thermostat, and hoses. Change the engine belt and tensioner. Plugs and wires, check the distributor cap. Listen to your fuel pump. Mine was whining, I replaced it. Etc. Look for potential problems and address them before they turn into real problems. Don't waste time and money on upgrades and mods.
 
Last edited:

gldixon86

Newbie
Joined
Aug 23, 2021
Messages
11
Reaction score
6
Location
Philipsburg, Pa
Yep agreed with all above, these trucks are pretty stout from the factory and usually factory parts are better than the replacements that you'll be replacing them with. Keep up on general maintenance and replace parts only as needed then get top quality parts like AC Delco, BOSCH, etc.

The only known weakness's in the 1500 models are the 4L60e trans starts slipping between 150k - 200k so that might be needed in your near future if it hasn't been rebuilt already. Start saving for that and find a reputable trans shop that is trusted in your community, or swap in a 4l80e. Another known weakness is the 8.5" rear-end. That can be upgraded to a 9.5" from a 6-lug 2500 model. Keep your eyes out for one of those with matching gear ratio as your front diff to swap in at your leisure rather than scrambling to find one when something goes wrong with your unit.
What goes/is wrong with the rear end I actually have had my trans rebuilt at 150 as it was slipping like ya said. But it’s good now but how do I know if my rear is going bad or is???
 

L31MaxExpress

I'm Awesome
Joined
Apr 21, 2018
Messages
6,041
Reaction score
7,832
Location
DFW, TX
Ditch the plastic or the rubber upgrade garbage intake gaskets and put a set of fiber paper gaskets on the engine. I glue them to the cylinder head and help them seal to the intake by painting the Gasgasinch to both sides of the gaskets and painting the cylinder head gasket face. I use a long 2.5" set of 5/16-18 carb mounting studs in the 4 corners of the head. Lay down the RTV per the GM service manual, lay the gaskets down over the studs to use as a guide, then line them up with the ports and seat them well. Next let the RTV get a little tacky about 20 minutes, line the intake up over the studs and it slides straight down without sliding around. Start your 4 center bolts, remove the carb studs, start your outer bolts. Go finger tight on the bolts, using only the 3/8" extension in your finger tips. Let the RTV start to cure, I use the 90 minute stuff and wait an additional 45 minutes to 1 hour. Now come back and torque the intake in 2 steps to the final torque value. Use the Edelbrock torque value since it was developed for those gaskets, IIRC it is 13 ft/lbs. My first pass is at 8 ft/lbs, 2nd pass is 13. I make 2-3 passes at 13 ft/lbs because the first bolts will be loose again as the other bolts provide additional clamping force.

The paper gaskets came with the Vortec TPI base I put on the Vortec head engine in my 83 G20 and held up for 15 years until I tore it apart and no signs of leakage and other than tearing apart from removal were solid. My 97 van had the OE gaskets fail in 2004 at 57K miles causing catastrophic engine failure on startup. Engine grenaded from hydraulic locking #2. I used the Felpro "Problem Solver" gaskets on the Goodwrench replacement L31 and they failed within 4 years, but I caught those leaking fortunately as coolant started seeping out behind the LH cylinder head, down the bellhousing. Actually that leak was one of the rear core plugs first because it appeared to be leaking out of the torque converter inspection cover. Pulled the cover only to see the core plugs dry, but the coolant dribbling down from higher up. Pulled the doghouse cover and saw it bubbling out between the intake and cylinder head. Rubber had delaminated off the stainless backing. Those gaskets are garbage, worse than the OE plastic with the encaplsulated rubber o-rings.

Plastic and rubber have zero usefullness sealing engines long term in critical joints. My 8.1L had the same style intake gaskets, but fortunately do not have coolant running through them. I could tell from the plugs it was drinking oil and all 8 intake ports had a comprimised seal open to the intake valley. Probably why they are known to drink oil and idle rough with higher mileage. Mine had vacuum leaks to the crankcase on all 8 intake ports, nice trails of wet oil from the intake gasket face of the head into the intake valves, but very little in the manifold itself.


 
Last edited:

Moofus02

I'm Awesome
Joined
Sep 21, 2021
Messages
239
Reaction score
308
Location
Michigan
Ditch the plastic or the rubber upgrade garbage intake gaskets and put a set of fiber paper gaskets on the engine. I glue them to the cylinder head and help them seal to the intake by painting the Gasgasinch to both sides of the gaskets and painting the cylinder head gasket face. I use a long 2.5" set of 5/16-18 carb mounting studs in the 4 corners of the head. Lay down the RTV per the GM service manual, lay the gaskets down over the studs to use as a guide, then line them up with the ports and seat them well. Next let the RTV get a little tacky about 20 minutes, line the intake up over the studs and it slides straight down without sliding around. Start your 4 center bolts, remove the carb studs, start your outer bolts. Go finger tight on the bolts, using only the 3/8" extension in your finger tips. Let the RTV start to cure, I use the 90 minute stuff and wait an additional 45 minutes to 1 hour. Now come back and torque the intake in 2 steps to the final torque value. Use the Edelbrock torque value since it was developed for those gaskets, IIRC it is 13 ft/lbs. My first pass is at 8 ft/lbs, 2nd pass is 13. I make 2-3 passes at 13 ft/lbs because the first bolts will be loose again as the other bolts provide additional clamping force.

The paper gaskets came with the Vortec TPI base I put on the Vortec head engine in my 83 G20 and held up for 15 years until I tore it apart and no signs of leakage and other than tearing apart from removal were solid. My 97 van had the OE gaskets fail in 2004 at 57K miles causing catastrophic engine failure on startup. Engine grenaded from hydraulic locking #2. I used the Felpro "Problem Solver" gaskets on the Goodwrench replacement L31 and they failed within 4 years, but I caught those leaking fortunately as coolant started seeping out behind the LH cylinder head, down the bellhousing. Actually that leak was one of the rear core plugs first because it appeared to be leaking out of the torque converter inspection cover. Pulled the cover only to see the core plugs dry, but the coolant dribbling down from higher up. Pulled the doghouse cover and saw it bubbling out between the intake and cylinder head. Rubber had delaminated off the stainless backing. Those gaskets are garbage, worse than the OE plastic with the encaplsulated rubber o-rings.

Plastic and rubber have zero usefullness sealing engines long term in critical joints. My 8.1L had the same style intake gaskets, but fortunately do not have coolant running through them. I could tell from the plugs it was drinking oil and all 8 intake ports had a comprimised seal open to the intake valley. Probably why they are known to drink oil and idle rough with higher mileage. Mine had vacuum leaks to the crankcase on all 8 intake ports, nice trails of wet oil from the intake gasket face of the head into the intake valves, but very little in the manifold itself.


Is there a better gasket for the 8.1?
 
Top