OK, so I'm new to big pickups. This one is a 1/2 ton with 5.3. Been modding my 94 Z28 LS1 for a while, so I get the points to set up for racing.

But this is NOT a racing truck. This is a tow vehicle and all around grocery getter.

One thing I noticed is that with the 3:42's in it, lockup does not occur till about 43 mph in 4th. I also noticed that torque is a little lean at that point with the engine spinning around 1,200 RPM. Seems that this is the knee of the curve, because once it gets to 1,500 RPM the torque in lockup seems adequate.

What of the common mods are proven to improve low-end torque? I know that 4:10's would have done the trick, but I'm also trying to coax as much gas mileage out of this as possible (a personal challange).

Also, what computer tuners (any available for 2005) will allow me to change lockup and shift points. I would prefer to fine tune and have the tranny lock up in 3rd also. Not sure that a Transgo would be the way to go, but done that before too on 4L60E's, so if that would help firm up the tranny let me know.

I know that low end torque and fuel efficiency are a bit off for this board. But there are a lot of knowledgeable people out there.

Thanks in advance.