I have seen both tire sizes, either one works fine. I ended up going up to 215/70R15, and never looked back. It ended up being a hire load rating, so it ended up being able to handle the car a bit more confidently, and filled the wheel wells out a bit more.

usually there is a label on the inside of the door that lists tire size for the car, or try the owners manual.
you'll find different tire sizes based on whether it's an Royale LS or just an LS. I usually go to a tire website and look it up.
Have fun!

Another suggestion, if you are in the mood for parts binging. 16" rims were extremely commonplace as well, and 17" and 18" can typically be easy to track down also.

If you are going to step up tire/rim sizes (225/60R16 is the common 16" size) you may want to look for 16 for summer tires, and put your winter tires on the current set.

And if memory serves, offset is measured in millimeters. Positive offset pushes wheels out, negative pulls wheels in.

I just ordered myself a set of black 15" steelies from Dorman. They're cheap, sturdy and I kind of like the look. Plus, if they get a bit of curb rash, I don't care. I like the width of the 215s on the car, and will probably go with the 70s, to fill out the wheel well.

https://cimg7.ibsrv.net/gimg/www.gmf...069dc9fbca.jpg
It finally got a bath. Work should start on it later this week.

I've had several of these over the years. We sold my 1998 LSS Supercharged last fall and still have a 1999 LS that is my sons daily driver.
Some items I've had are listed in this thread, some are not.
1. Lower Intake fix. The substrate of the plastic gaskets fails allowing coolant leakage. Every GM V6 I've owned has had to do this fix. You will have two options, the OEM plastic gasket or a steel version. I've never had the steel version ever fail. It's cost is competitive to the plastic one.
2. Valve Cover Gaskets: frequently fail.
3. Oil Pan Gasket: Victor Reinz brand I've found fits best. I've found other brands were up to a 1/4" too long.
4.Ignition modules: Often go bad past 100k miles
5. Spark Plugs, Wires, PCV: Might as Wells...
6. EGR: Some engines they last forever, others not so much.
7. Throttle Body: Some engines require frequent cleaning, some do not. Throttle will feel sticky and/or have some effort to get past the ridge.
8. Cooling System Elbows: On the passenger side, there are a pair of 90 degree elbows. The o-rings fail and plastic cracks. There are metal versions available, get those.
9. Accessory Belt/WaterPump/Pulleys/Tensioner/Alternator/Hoses/Thermostat: Replace all of them. Age/corrosion/wear...
10. Filters: EngineOil/Fuel/Air/Trans Oil. Replace them all
11. Oils: Brakes/Engine/Trans/Pwr Steer: Replace them all. Brake fluid is clear, not supposed to look like coffee. Engine oil, use Synthetic, change every 5K. Trans, drop the pan and change the filter, reuse the gasket unless damaged.
12. Air suspension (if equipped) is difficult to repair. Just convert to normal strut system.
13. Front Doors at grab handle, typically vinyl cracks. Good Luck finding a door car in a yard not already cracked...
14. Replacing accessory belt requires a PITA process of loosening items on the drivers side that will leave you shaking your head.
15. If oil or coolant has been leaking into exhaust path, the cat won't last long. Cat and both O2 sensors will need replacement.
16. Power Antennae: Original is long out of production, easy replacement through the trunk. aftermarket brands available.

https://cimg8.ibsrv.net/gimg/www.gmf...6cd0d7457.jpeg
https://cimg0.ibsrv.net/gimg/www.gmf...c2eaab535.jpeg

Wow. NICE LSS. You could serve me dinner on that engine bay. Mine is filthy with road dust. You could certainly give me some tips on cleaning that up.

I'm confused about what you said about the lower intake gasket. The first time I read that I was thinking of that plastic upper intake plenum (which sounds like one of those "when not if" part failures. If there's a steel version of that, I want it.). Which lower intake gasket are we talking about? The one that meets the upper intake, or the one on the engine side? I may have that all wrong...I've watched sooo many YouTube videos.

Thanks to the tips I've received here, this is what preventative maintenance I've planned:
new engine, trans, brake, coolant fluids
serpentine belt
cooling system elbows
fuel pressure regulator
transmission modulator thingy
trans filter and pan gasket, with new pan magnets
transgo shift kit
all new shocks and struts (needs new tires, too)
general maintenance inspection for hoses, brakes, brake lines, power steering, A/C system, etc.

The thing drives beautifully and I want to keep it that way.

BTW, guys (and gals) the CD player doesn't work. It's a double DIN setup and looks like a nightmare getting it out of there. What's been your experience?

As always, many thanks for your advice and expertise.

Stoners Trim Shine is the product I use, it is fantastic, I buy it by the case. I bought mine off amazon but I don't do business through that anymore. I use degreaser and scrub (warm engine, not hot). once a thorough scrubbing with a variety of bristle brushes. I somewhat protect alternator and module packs. Use a house hose to rinse it off. Let it dry and then start spraying Trim Shine.It will stay nice for a long time. Don't have to do anything else!

There is a pair of lower intake gaskets that seal the engine to the intake manifold.
Fel-Pro offers a kit (MS 98014 T). The substrate is steel, not plastic and seal surfaces are molded to that substrate. It's on RockAuto if you use them or your favorite local brick & mortar store. The pic I borrowed shows the kit.
https://cimg8.ibsrv.net/gimg/www.gmf...d0067cedbf.png

The picture below shows delimitation on the RH side between the plastic substrate and the molded seal. This was taken off a 24K mile 3.1L in my wife's 1998 Cutlass. The same thing occurs with the 3.8L as well.

https://cimg4.ibsrv.net/gimg/www.gmf...983b0e544.jpeg

I have a TransGo kit here I never used. It can be installed with the engine in the car but is a ROYAL PITA to do. I'd pass on that one unless you have to pull the engine or trans in the car, then it is easy.

This document may be helpful to you.... please see the attachment.

Regards,
Mike

In the Fel Pro kit picture above, those six small o-rings are your for your injectors. Cleanliness is important. I have a solvent tank so cleanup is easy but not everyone has one of those. Before you pull the fuel rails make sure you don't have debris sitting on top of the injectors. If there is, as soon as the injector is pulled out of the hole, that debris can fall in to the engine. I use a vacuum and some light compressed air to pull the debris out first. Once the intake is off, you can use Carb Clean or Brake Clean on the intake to get it in order for reassembly. I have a strong bristle brush to run through those injector holes to clean them up. Run a pinky finger to confirm no ridges in the hole, it's usually dirt build up. That o-ring is all that keep your system from leaking so clean surfaces is your friend for a proper seal.

Think I'm gonna let the pros handle that. I replaced the wiper blades and air filter. That's pretty much the extent of my wrenching abilities. LOL