2004 5.3 RCSB my daily driver and tow vehicle ..........any value in installing UD pulleys I have them on race cars etcetc and my thinking is they really only ad pwer / torque at higher rpm .......Am I thinking correctly or would there be some value on low rpm tow vehicle

 

Pullies show a few HP across the entire RPM band. It does add power, but usually you would leave that to the last thing to do as a bolt on after intake/exhasut/etc. With a tow rig and low RPM, be sure to get the kit with the alternator overdrive pulley as well as the main crank pulley so that you don't run into voltage issues. You may also want to upgrade your alternator to a 145 amp unit if you don't have one already (50 bucks or less from car-part.com salvage yard search).

 

yup..hes right

 

Thanks for the replies you confirmed what I experienced on previous 01 truck with UD pulleys ....... UD pulleys will not be one of my high priority mods for this truck .........starting with Magnaflow large case muff on stock system and a set of Doug Thorley Tri Y headers and maybe a CAI or modified stock box and of course a PCM tune after that not sure any bolt on engine mods of any any real value for improved towing although since it an 04 E-fans is something I pbly will do ,had them on last truck an 01 and although not convinced saw any power or mileage improvement liked the consistant cooling when towing .......

 

Will the AC still blow cold at idle or a stop light?

 

I wouldn't do it on a tow rig. It will slow down your water pump and you may run into overheating problems.