I have a 2003 1500 Reg Cab 2wd with a freshly rebuilt 4.7. Truck is all stock w 17" wheels and need some suggestions to increase towing performance. Truck has trouble holding speed especially with wind. I'm Towing a 19ft bass boat and a 16ft airboat which has a lot of drag. Can only run 60-65mph. I'm thinking gears might be the solution? What is the optimal gear ratio? Pretty sure I have 3:55 right now. Will exhaust, CAI, and throttle body spacer help as well?

 

Your best bet is 4.10 or 4.56 gears. Those 3.55's are killing you.
The Exhaust, CAI will help a little, the TB spacer will do nothing.

A tuner like a Diablosport Predator or Superchips will help too.

 

Gears for sure! I'd go straight to 4.56s if it were me. You might lose 1 mpg when not towing or hauling on the interstate, but you gain at least that in town and do WAY better when towing, not to mention you'll pull easier and save a ton of wear & tear on the transmission by not having to shift or "hunt" for the right gear nearly as often.

Where you at, sounds like you might be in Florida? I know of a real good shop on the east side of the state where I've sent a good half dozen guys for gears. He might be a tad higher now, but last I sent someone there (summer of '09) he was only $600 per axle for gears, install kit & labor. Most guys on these forums are shocked when they see that price as they get quotes sometimes for double that price.

The guy ain't done a bad install yet either, has never had to re-set the gears because of whine.

 

You got it! I'm in Florida. Also, will the type of differential have any impact? What is stock differential on a 03 reg cab 2wd w 4.7?

 

What is the general consensus here for make/model of tuner?

 

With a 4x2 you can go all the way up to 4.88s in the rear, you have an AAM 9.25" 12 bolt, 31 spline rear end. As stated you have either 3.55 or 3.92 gears (probably 3.55s in that setup but it could have been ordered with optional 3.92s).

As far as the tuner, Superchips is the best option for an '03 4.7. You'll get some modest gains but nothing that'll quicken your heart rate by any means. Worth the money, but won't do near what gears will.

Free flowing exhaust (the big thing here is to ditch the stock "Y" for one that isn't crimped down to nuthin') helps for sure, CAI will add about 5-7 RWHP when combined with the better breathing exhaust. Make you one out of PVC for about $20 (plus filter), I've made and tested these and you get the same gains as any store bought CAI that takes it's air from in the engine bay in the $100-300 range. Some of the high end ones (Vararam) have better gains, but they get the air from WAY too low in front for consideration on truck that sees any water or mud (hell the way we get standing water on the roads during heavy rain down here, you'll hydralock on pavement with a Vararam or that type of CAI).

Throttle body spacers do nothing more than whistle on a modern TB, NO gains whatsoever, and I've known guys to loss a MPG or two with one. They had their day in the early TB designs but they are do-nothing dinosaurs today...

 

Thanks for all the great info/input. I found a free VIN decoder here on the forum and was able to obtain a build sheet for my truck. I have a 3:55 rear end. Would like to know the name of the shop you recommend for gear swap here in Florida? Gonna do the gears first then most likely a Magnaflow Y pipe. What muffler do u recommend including size and inlets in/out? Want a nice moderate rumble but nothing too loud and not much cabin noise either.

 

Yeah, it's Cocoa Beach area. TJs 4x4 Warehouse. Small shop but they do excellent work at damn good prices. I hope he's still there, never know in this economy and I haven't sent anyone or been by there in probably seven or eight months.

I have their number at work on my PC, (newer cell and I just checked, I didn't put it in there). So if you don't find the listing, I'll post here with it tomorrow.

Maggy muffler is a good choice, mellow and they flow well. The maggy Y is great, stainless, flows well and is only about $25. I wish I knew they existed way back when I re-did my exhaust/headers/etc. I had a local shop fab me one up, carbon steel so it's not gonna last forever. It's 500% better than the stock one, but not near as free as the Maggy.

I run a Cherry Bomb Extreme, if you don't want to wake the people up four houses down the road, trust me, you don't want it, LOL...

 

Your truck is probably like mine was, and has an open rear diff. I installed a PowerTrax LockRite (from EastCoast Gear) in my driveway. It acts like a spool/solid diff on straight roads, but ratchets around turns. It can be noisy at times, but I don't care. I can drop the hammer and take off without one wheel spinning. Very nice in winter.
If you plan to tow a lot, your 17s are best. 20s are heavier and usually bring a taller tire, making towing even harder. I'd change your Y pipe and muffler. A Magnaflow with a long case should serve you well.

 

Where is a good place to order gears/ring & pinion sets with good pricing? What brands are best? Any to stay away from?