Re: mods for my stock XB
Leave the stall till later when you have sorted the engine and rear axle ratio.
Speaking of which, what rear axle ratio do you have? Look closely under any diff-cover mounting bolt for a tag. The 6 digit ID number will begin with 199 and the next 3 digits will tell us what you have. If it's a 302, it would most likely be an integral carrier, which came in 2.92, 3.23 & 3.50 ratios. If you can find a 3.50 from, most commonly, a ute, that can be cheap upgrade.
A very easy improvement can be made in acceleration by lowering (numerically raising) your ratio.
Engine wise, a dual plane manifold would be a good start; an Edelbrock Performer 2V would suit a budget combo.
Think outside the sqaure with regard to carburation too, for a mild 302 a Cater AFB, now sold as Edelbrock, are an excellent highly tunable carb that give good across-the-range performance.
When you settled on a carb/manifold combo, decide if you're going to remove and do anything to the heads.
Lastl of all, think about a higher stall. On a mildly modified engine, it effectively waste fuel; that's about all. Maybe leave it and spend your money on other mods.