guys, my rear sight is not adjustable as it seems. Its fixed with a step ramp. My front site is dove tailed and can be moved left to right. I think this is the only way to site this gun.

I bet that rear sight is adjustable for windage. Never seen sights on a lever gun that weren't adjustable on the rear.
I could be wrong but I doubt it. Drop by a gunsmith and get his verdict.

Which site moves is irrelevant. Just drift it with a brass punch or wooden dowel, or build one of the screw presses I mentioned earlier and be done with it.

8" at 25yrds might be a lot bigger issue than just adjusting your sites. 8" at 25yrds vs a 20" sight radius = ~1/6" of drift needed on the sight (if you have a micrometer caliper, use that to determine how far you drift it, especially if you use a punch and hammer).

Why not just scrap the factory rear sight and install a Williams adjustable peep?
It's a much better sight and completely adjustable without special tools.
Not expensive either.

just talked with Marlin and they say the only site that can be adjusted on the 336 is the front site. It looks like they have put all different kinds of sites on this gun over the years. apparently my front sight is the only sight that can move.

Well I guess you learn something new every day. My last hands on experience with a Marlin lever gun was back in the 1980s.
Things have changed.

Good luck working out this problem.

Incorrect, according to all 336's I have seen. Check out the diagrams at the link below. If your gun has parts 40 and 41, and the barrel has a dovetail slot for the rear sight, the rear is adjustable. Sliding part 41 forward and back will change the POI elevation. Sliding part 40 left to right will change the left to right POI.

If your gun does not have these parts, and the dovetail slot, the sight should still be adjustable for elevation.

http://www.bing.com/images/search?q=...electedIndex=6

thak you for the schematic.. mine looks like this but there is no dove tail on the rear sight. It has what looks like 2 tapped holes on the top of part 40. They are not screws but look like pegs that are flush with the top of part 40.

Seems like a cost-cutting measure.

As I noted in an earlier post, I really like a peep on my Marlin. I'd remove the rear sight and go that route. You still may need to drift the front sight a little.