Is that a Chevy 1500 Dan? I'll bet your 30ft trailer exceeds the tow rating of that truck. You mentioned a lot of things you did to upgrade the engine and the cooling system but what about the drivetrain, suspension and brakes?I am trying to find a shot of my poor old truck. I had started to repaint it wit the silver with black top and bottom like it was new. Accident stopped that an after putting new nose on it I just haven't finished it. One of these days....
I had a 30ft trailer that weighed in at 10,000lbs loaded. I originally towed it with a 1997 Suburban 2500 with a 454 engine. It could handle it but I felt it was working too hard so I traded that in on a 2005 Silverado 2500LT with a Duramax diesel engine and an Allison transmission. That thing was a real towing beast! I could pretty much just set the cruise control and it would effortlessly climb any grade I encountered. The temp gauge rarely went above normal on it and when it did it was barely noticeable.
Loved that truck but we got rid of the trailer last year so didn't need the truck any longer. Sold it and bought a 2013 Suburban 1500 with a 5.3L engine which is beefy enough since the most I'll tow with it is a 10Ft utility trailer. Got the Suburban just before the pandemic thing hit so have only driven it a few times.