They're close to stock so technically should "fit" but there's some things to be aware of.
1. The stock set are 20 x 8 with 54.65 offset, so a 20 x 9 with 20 offset will push the tires out roughly 1-3/8". Although you'll be adding clearance form the suspension, you could potentially encounter rubbing with the wheel well liners/bumper/fender when turning hard. Since you're keeping the tires the original size, you're likely to have enough clearance but something to consider. Maybe once you pick the truck up, crank the wheel all the way over and measure to see if you've got 1.4" of clearance. If so, you're good to go.
2. The bolt pattern you noted (8x165.1) is accurate so no worries there. However, the stock center bore is 121.3mm so using a wheel with a 125 mm CB will be bigger than stock. The upside is it'll fit on with no issues, but the nuance is that you're no longer hub-centric. That means you'll be relying on the lug nuts to center the wheel onto the hub (aka lug-centric). 3.7mm is fairly small (roughly 1/8") but you may be able to find a ring to fill the void. **Not a spacer to push the wheel out more, a "hubcentric ring" to center the wheel on the hub.
On a 1500, or a light SUV I wouldn't worry too much about running lug-centric, but a 2500/3500 I don't want that gap. That is assuming you're going to work the truck. If it's just a commuter or a toy (no shame in that) then lug-centric isn't that big of a deal. Some will say avoid it like the plague, but others will say they've done it for years. I did it with a car and had no issues, but not something I'd do with my truck.
Hope that helped.
