Effective changes that can be made, if any?

[Bex]

To my GMC 2500 van.
Its a 1993 G2500, tagged as a 3/4 ton but it has half ton axles.
Its got the 5.7lt engine and 3:42-1 rear end.
I pulled our 28ft Argosy home for a 9 hr journey over mostly rolling hills and it was "OK"
I am a very steady driver and 100kmph is fine with me, just enjoying the scenery as I go, In fact this was my first time ever pulling anything and it was an easy, stress free experience. But the hills did take their toll on my speed.

Now, before I change vehicles are there any significant (or minor) changes that I can make to the van to enhance the performance?
I am currently searching for a 3:73-ratio rear, but that's about all.
I installed a transmission cooler on it as well.
Is there much more I CAN do?
Advice, as always, greatly appreciated.
By the way, the GMC has only about 280k KM on it, so by no means "over the hill" yet.

Cheers!

Bex

[HowieE]

The rear is a first.

The trans cooler. Did you install it before or after the radiator. It should be After.

Considering the age of the truck I would pull the radiator and have it roded and cleaned. Canada is OK with the 3 core radiator put a 4 core would be nice if you are headed south.

Not sure what trans you have but look into a BD Torque Loc. That will allow you to lock the converter in any gear above 33 mph. Great for pulling hills, in 2nd or 3rd, without cooking the trans.

[Bex]

Not sure if a torque lock is for a gas or diesel engine?
Mine is gas.
The cooler instructions gave two installation options, better and best, and I followed the instructions for best, I dont remember which that was but presume it was after.
I have read about "cold air intakes", what are they and would the van benefit, if it can be installed?

Bex

[HowieE]

Cold air intakes route outside air to the air cleaner assuming the cooler air is more dense and thus more air per charge cycle to the cylinder. This will have some effect at higher RPMs but not sure it is what it is cracked up to be at lower RPMs.

A lot of Vans have this feature built in because of the tight quarters under the Box.. You will see the air cleaner ducted forward to before the radiator.

[Jammer]

The axle ratio change will make life easier for the transmission but won't make the van go any faster.

Watch temps on everything.

Anything you do to hop up the engine power will make more heat and cause failures in and around the engine compartment. Vans in general and that era GMC with the 5.7 in particular have problems getting enough cooling air to the engine and accessories and so you get failures not because the water temp/trans fluid temp is too high but because the air cooled components are running too hot, alternator, ignition, air conditioning, that kind of thing.