Hi Reaper - welcome to the forum.
Have you had a chance to go through these pages?
65+ Efficiency Mods &
100+ Hypermiling Tips
The cheapest, quickest route to savings is adjusting the nut behind the wheel (you). You need an instant & resettable trip MPG display to do this properly & to maximum effect. Don't balk at the price of a gauge -- it'll pay for itself fast in a vehicle that consumes a lot of fuel.
Also, are you recording your tank to tank mileage now? That's another key, so you can see the motivating effects of changes to your driving & mods to the Blazer.