I don't have a Guide gun, but I used to have a Scout in .308 and still have an Alaskan in .375 Ruger which I had threaded for a suppressor.
The good news: On my .375, I can just barely see the irons over my Rex Silentium MG7. The sights on the Alaskan and the Guide Gun appear to be the same, so you may be in luck there. The MG7 is about 1.75" diameter, so if you stick with a 1.5" diameter can you will probably have some margin.
My Scout was also suppressed, but I never used it without a scope, so no idea if the irons cleared the can. It uses different sights anyway, so not really relevant.
Now the bad news: Ruger seems to be in love with using nonstandard thread pitches on the Guide Gun, Alaskan, and African. I just checked and sure enough, they advertise the 30-06 Guide Gun as having a 1/2-24 thread. I'm sure you could get a thread adapter to a normal thread type, but a 1/2-24 doesn't leave a whole lot of meat between the bore and the root of the threads. Personally, I won't use any 1/2" thread on the .30 or larger rifle due to the thin barrel wall.
If you do want to suppress, the Scout might be a better option since it comes threaded 5/8-24, but it isn't available in anything more powerful than .308 to my knowledge.
I was somewhat lucky with my .375 Alaskan in that mine is an older one made before Ruger was threading them, so I could choose my thread form. Current models are 5/8-18, but I chose 5/8-24 for mine.