its been a while since i last visited the site but i was have trouble finding the white spacer mod post that actually shows pics and step by step instructions.  could anyone direct me

Some claim to do it w/o taking the tank off,...good luck.
Take the top cover off the carb, and remove the plunger that contains the needle/spacer assy.
Caution,.....!!
don't mess up the heads on those tiny little philip screws that hold the needle/spacer in the plunger. They are very tight, and require a good proper fitting driver w/ lots of body weight, or a "mini" impact driver to loosen them.
I will add this from my personal experience,......
If you are doing a 1/2 spacer mod to improve a ragged running low end 1/4 throttle situation, you are right on track. But if you are doing it only to lessen deceleration backfire, get prepared for a big disappointment !

So, I am still getting decel backfire (small pop-pop-pop).  I just rejetted to

55 pilot jet
152.5 main jet

no spacer mod and stock spark plug.
cone air filter and dyna muffler.  There seem to be no leak on the header/muffler when I checked it.
2 1/2 out on air/fuel.

What should I adjust at this point?

Stock savage for the most part (see sig)
I don't get any backfire while riding.....I do get one very quit "puff" once I shut the engine off.