I have had a '19 XL (supercab), a '20 XLT and now have a '25 XLT FX4, all with 2.3L. I did not try the 2.7L, but I find the 2.3L to be peppy and perfectly adequate. I wanted an XLT 4x4 with towing and advanced electronics. The XLT's that had what I wanted also had the FX4 package so that's...
The answer is the 4 foot wide sheet doesn't really fit between the wheel wells with the liner. Possibly with some heat (Hot sun or heat gun) and weight you may be able to stretch the opening but you risk damaging the liner as well.
Can you lay a 4 ft wide plywood sheet flat between the wheel wells? I just bought my G6 yesterday and measured. It looks like the sheet will just fit without a bedliner.