Joe - my rig came with two group 27s in a battery box. I decided to stay with group 27 because they fit the battery box that came with the unit. I googled the "difference in group 24 and 27" and found this interesting article...
https://www.uetechnologies.com/group...d%20a%20charge
...but I don't see a compelling reason for one over the other. If your group 24s have lasted 5 years that seems pretty good to me. I replaced my original group 27s at 3 years with Duracell AGMs from Sams ($199 each). We were without power for 5 days in the December 2022 ice storm (12* for several days). When the storm was in the forecast I decided to run the furnace out in the Monte at 50* because I did not winterize the Splendide washing machine. I had not counted on loosing power for five days with temps in the teens. The batteries were drained to dead and did not charge back to a comfortable level. (We were lucky - the washing machine was not damaged from the freeze) Sams does not carry Group 27 AGM any longer (they claim there was not enough demand to keep them on the shelf). I decided to go with their lead acid Duracell group 27s.
By the way - I remember you from the North Texas pop-up camping club. It's been a long time!