Dunno there Drfife, spoken like somebody who knows that they are flirting with the limits. Nice rig BTW. Had a look at the specs. Your LOA is the same as my Alpenlite but with a near 14,000 dry weight you are about 2,000# heavier than me. No doubt it is that much better in-house built frame that you have.
The truck numbers are the truck numbers but the more you are within your numbers the more secure you will feel when the stuff hits the fan. It is common to see people here, who have SRWs, saying "Oh ya, it pulls just fine". It is also common to see people who have gone from a SRW to a DRW saying "I'll never go back to a SRW. It is like night & day".
Now, I don't advocate a 3500 DRW to pull a teardrop trailer but when you are in the territory of a mid to large 5er with dry weights exceeding 11,000#, it sure is nice to have well more than enough truck to pull & stop it.
We have done Alaska 3 times, every other state at least twice, well over 100,000 trailer miles & the last thing to be on the mind is, "Are we over weight spec?".