So what makes my 97 more powerful than the 96 (talking if theyre both stock )

 

As far as I know, there should be no difference between 96 and 97. The year breaks for semi major engine redesign are as follows for the inline six (If Im wrong Im sure one of the senior members will correct it):

84~86: carburated 4.0L, an upgraded version of the old 4.2L
87~90: RENIX fuel injected 4.0L, about 170hp, usually the most talked about when referring to strictly 4.0 vs 4.0 HO
91~95: OBD I 4.0L HO (High Output). Pretty much all engines after 90 are about the same horsepower, with these being 190hp. Magor difference between these and the earlier engines is the head, which was redesigned for better flow, and is the main reason for the power increase. This year is non-adjustible, non-chippable, but pretty much bulletproof in my experience as far as the electronic system is concerned.
96~98/99: 4.0L HO OBD II. Almost identical to the earlier '90s HO engine, but with OBD II computer. There may be some adjustments that can be made, superchips, whatever since its OBD II, but otherwise still 190hp. Ive heard some conflicting information of late on the 99 model year, so you probibly want to make sure what you have if its a 99. Somewhere around 96~97 there was.a reinforcing runner put in the head for durability, but it did not affect performance.
99/2000~2001: head redesigned with smaller exhaust ports for emmissions, as well.as 3 catalitic converters. This netted a power decrease for the engine as a whole, so they redesigned the intake to compensate. It is billed as a 193 hp engine. Later on in this subgroup coil on plug was added, but other than cost I dont know how this affects performance.

A side note: as you state that this is about stock tech, it would have been more appropriate in the regular Tech forum.

If you are talking about the difference between 96 and 97, there should be no difference at all in performance unless you have a problem with one of them. 86 and 87, however, will have a vast difference, as one is carburated and one is multipoint fuel injection. I cant remember off the top of my head, but the difference may have been as high as 20 hp, but the exact figure is around, just do a search.

Also, if you have one as an automatic and one is a manual trans, you will see a difference in performance, as an automatic takes power to control itself. A/C can play a role as well, and other things like tire size and gearing, oil, and maintenance can change things more than one might think.

Of course, make sure you arent comparing a 4 cyl and a 4.0 HO, there is no comparison, other than the 4 cyl is in some respects like a six with two cylenders cut off. In the 90s you could actually swap between the two engines with the same computer and it would just work, at least on the OBD I generation.

Hope this helps someone. More specific info is on wikipedia, as well as transfer cases and axles, gearing, etc.

 

Probably the programming of the ignition & fuel delivery curves in the ECU - timing, as they say, is everything (particularly with ignition...)

 

ha. ya, utah and california suck (as far as most laws go). utah is almost a mirror image as far as laws go in alot of cases....lol california is totally gay though.....their gun laws make me sick. complete lack of common sense. sorry guys, ill do it lol