2000 chevy 2500 ext xtd cab lng bd 454

I'm considering buying a 2000 chevy 2500 4x4 ext cab lng bd with

100,000 miles for $10,000. I'm pretty sure it has a 7.4 454 vortek engine. I landscape and plow. I need an 8 ft. bed. I frequently pull a 5,000lb. load. I don't care about gas mileage because I only use the truck for local work and I don't travel far distances. I have read posts where people claim the get-up on a 454 will snap your neck. I test drove the vehicle. Unfortunately the salesman was with me. I wasn't able to play around, but when I pulled out of the lot it only felt like a regular powered truck. I suppose I was trying to be poIite in front of the salesman which kept me from stomping on it as we left the lot to test out what it's got. As we went onto the highway I gave it some luvin' and noticed some rapid acceleration but it was almost too smooth. I was expecting to be thrown into the back of my seat. I own a Dodge 2500 reg cab 4x4 lng bd 5.9 360 and when I step on the gas, I don't mean stomp on it, but liberally apply pressure to the pedal I can feel a sudden presence of power, rapid sinking into the seat best describes it. If I stomp it at a dead stop my tires are easily spinning. Does any body own a vehicle similar to the chevy that would like to comment on the amount of power I should notice out of a 7.4 454, or if there are any typical problems with this truck or engine. By The Way:::My Dodge has plenty of power/no trailer- but with trailer (5000 lbs.) the truck will sway at speeds over 45mph, has trouble going up steep hills, and horrible braking. Maybe I should drive my trailer loaded down to the dealer and test drive pulling a heavy load. My mechanic claims chevy to be a safe bet. He also spits on anything but chevy. I have no preference. I'm open minded. I just want to know I'm putting $10,000 to good use. Any help or advice would be great. Thanks.