My 3100 fully loaded with fluids and two adults and 80 lb dog tipped the scales at 13,600 lbs, 4460 on the front axile and 9140 on the rear, I did not get individual corners done. That leaves me with approx. 900 lbs of extra stuff.
The 13,600 lb GVW was the coach completely loaded with all the gear and food I would need for a week on the road plus myself and my wife and dog. The holding tanks were empty. I was looking for a little more capacity but 900 lbs is not bad compared to say a Sprinter that is about max before you load anything. I do not know exactly what the weight of the dual pain windows might be but the 3100 does have a fair number of windows and glass is not light so it would have to be at least 100 lbs that takes fuel to move down the orad. Enjoy the 3100!
The weight distribution on your 3100 looks pretty good and falls in line with the Ford Bulletin Q-18 R5 "Gudelines for Modifying Ford Light Truck Wheelbases". An excerpt from that bulletin:
II. COMPLETED VEHICLE WEIGHT ANALYSIS
Ford requires a weight analysis to be performed on the complete vehicle. Some considerations
for such analysis are as follows:
• The Maximum Vehicle Loading should include the Unloaded Vehicle Weight (UVW), 150 pounds
for each passenger in all designated seating positions and sufficient payload capacity for reasonable
assumptions of cargo and trailer tongue weight. The maximum vehicle loading shall not exceed the
OEM chassis Gross Axle Weight Rating (GAWR), nor the Gross Vehicle Weight Rating (GVWR),
as identified on the front cover of the "Incomplete Vehicle Manual" (IVM).
• Avoid rear frame extensions or vehicle configurations that may allow the customer to distribute the
vehicle load so that significant front unloading can occur. Ford recommends no less than 35 percent
of the total loaded vehicle weight be maintained on the front axle for most vehicles included in this
report. The E-450 should be no less than 32 percent. The F53 with a GVWR of 20,500 pounds or
more should be no less than 34 percent (or 30 percent for any F53 with a tag axle). Inadequate frontend
loading could adversely affect the steering and braking characteristics of the vehicle.
• A road test should be conducted on a completed vehicle with a payload representative of the user’s
likely worst-case application. This test is recommended to qualify the ride and handling
characteristics and support the weight distribution analysis.
For the E-450, the bulletin recommends no less than 32% on the front axle and your front axle is at 32.8% with the front weight 540 below the 5000 limit and the rear weight 360 below the 9500 limit.
My 2551 fully loaded for a trip weighed 4400 front and 8000 rear, 35.5% on the front axle.
Apparently, having less than the recommended weight percentage on the front axle would affect handling. It is interesting that Ford recommends the E-350 to have no less than 35% on the front axle vs 32% for the E-450.
The Ford bulletin can be found here: https://www.fleet.ford.com/truckbbas/non-html/Q18.pdf