2000s suzuki vitara v6 top end rebuild?

Helping a guy from work, bought a car with the expectation of having to fix it, described top end noise consistent with tired hydraulic lifters. Cam over arrangement.

Is there any reason, provided cam bearing surfaces and lifter bores are ok that it wouldn't be straight forward to do valve stem seals (worth doing guides?) Lifters and replace factory cams. The base circles of the cams are visibly marked but only one can be felt with a fingernail.

I have access to a reasonable range of tools and measurement equipment.

I have some pictures but can't seem to upload from my phone, I might email them to myself and add them later.

Replacing valve guide seals is a simple and worthwhile part to replace if you've got the head apart, particularly if it's high mileage and burning oil on over run. Quite often though the reason the valve guide seals leak is because the guides are worn, in which case replacing the seals is a short lived solution. There will be specs in the manufacturer's workshop manual for valve to guide clearance but this can be tricky for the average novice to measure. It's one of those aspects that you tend to build up a feel for over time by rocking the valve back and forth in the guide (spring and retainer removed obviously).

If you're dealing with a hydraulic lifter arrangement then your life is greatly simplified as there's no need to set valve lash.

Yes, i have helped a mate reshim a desmo ducati, providing there aren't any catches with the hydraulic lifters I assume it is much more straight forward. I will spend some time digging through the workshop manual.

I can probably set up a basic spreadsheet and mess about with a dail gauge knowing the valve and guide spec and engagement length to get a decent idea, I will ask our dimensional guys if they have any simple stuff for measuring those small inside diameters directly just in case there is an easy way, they have a carbide (?) stepped pin sample set but I don't know if I could borrow it over a weekend.

About the only caveat is accessing the spring caps to compress them for removing and refitting the collets and holding the valves up in place - fabricating a fitting to screw into the spark plug hole and running high pressure air into the cylinder can work well with some engines - are you doing this with the head on or off?

Thanks. Will strip the whole thing down as the cams and noisy lifters are suggesting it may not have run with enough oil or thinned with age, suspect poor maintenance by the previous owner so will strip the lot. I was curious if there were any tricks with springs and retainers but being a standard thing i don't imagine it will be too tricky. Seems you have to pull half the car apart to get the engine out, I was hoping being north south it might be a bit easier.

If you haven't done so, pick up one of the Haynes, or similar, workshop manuals and have a good read first - sometimes there is a simple action that can make things much simpler.

Depending on the engine design, you may need a deep throat valve spring compressor - and when re-assembling don't forget the trick of a dab of grease to hold the collets in place before releasing the compressor.