We had a similar setup, but through a vintage tube fender amp. We put an sm57 right against the mesh in the center of the cone and ended up getting a great sound, but it's not always as easy as just sticking it up there and expecting a good sound. The sound you'll get depends greatly on what equipment you're playing through. In my mind, the goal is to replicate the sound you hear as closely as possible.

You may try a large diaphram condenser a few feet away and see what you get. Play around with mic placement and mics. Try the sm57 moved closer/farther, and also move it towards the side of the cone. Try another cone if there's more than one! They may sound different! Just experiment until you get a sound that you like. You may need to throw a little EQ to touch up the sound a bit too. Like I said, experiment.

A recording would be helpful.

Like most cardioid mics 57s and 58s are notorious/beloved for their proximity effect (emphasizing the bass when you put them up close to the source amp, guitar, vocalist, whatever). A lot of people like it because it's a very familiar sound - then they roll off a bunch of the bassiness with EQ. I never understood that approach, but that's what tons of people do.

I agree with Mauisnow experiment with mic position, you might find a spot that's a little brighter out around the edge of the cone. If it's the only mic you've got I'd try moving it around.

Start with the mic clear out by the edge, right against the grillcloth
Start the recorder
Play guitar for 20-30 seconds
Then with the recorder still rolling, move the mic a half inch toward the center
Experiment with the angle too
Say outloud what adjustment you're making to the angle or position. (so it ends up on the recording)
After 10-15 minutes you should have worked your way to dead-center
Playback should indicate if there's one place you think was the least dull as you worked your way across the radius of the speaker
If you're meticulous about the 1/2" increments, you should be able to get pretty close based on your recorded description
If you haven't found anything you like, you might have to back the mic away from the cabinet a little at a time
Then fine-tune it from there

On my Mesa 1x12 combo, the brighter sound I was looking for was about an 1 1/2" in from inner edge of the "surround" angled in toward the edge of the "dustcap" about 10 degrees. But, I wasn't using a 57.

[[url=http://[/URL]="http://en.wikipedia…"]Anatomy of a Speaker[/]="http://en.wikipedia…"]Anatomy of a Speaker[/]

I hope that helps.

what chain do you have going into your amp.you say 90's classic rock although a deville is really more of a country amp.
i use to have a hot rod deluxe that i used a keely compressor on with a boss overdrive pedal and that made it sound pretty classic rock wich i also like.
i use an sm7 on a deluxe reverb now although the 57 did just fine.
i would say get your chain going(whatever it is) till you like what you hear 3 feet away from your amp,then try the 57 in the grill at an angle an inch away from the edge pointing towards the center.
get a stong hot signal into your daws, -10 or so cause your not likely to add plugs if it sounds good and a little e.q. won't matter. you'll mostly be cutting anyway.
it's worked for me on occasion.

"I never understood that approach, but that's what tons of people do."
dvdhawk....im incorigible, i still do that.lol