I'm purchasing a 1984 Holiday Rambler 30' Motorhome w/ a stock Chevy 454 motor & TH400 transmission. The stock power ratings on these engines are pathetic (240 hp/355 tq), ie: peanut-port, open chamber, small valve heads , low compression cast pistons (8.25-8.5:1), low lift/short duration hydraulic cam, cast iron intake, Q-jet carburetor, (4 bolt main / steel crank).
How do I free up more horsepower / torque, while also making it more effective for towing? I want a 454 that can handle our coach, tow a small vehicle, and pass slower 18 wheelers comfortably w/o overheating. Any advice or information is greatly appreciated.