I run a marshall head through ampeg cabs and can get some nice crunchy results. try different things out and determine if you want tubes or solid state, I think there are some hybrids out there as well. There's also the option of letting your effects get the sound and have an amp with the best possible clarity to bring that through.
Marshall's are too muddy and unclear to me...
The best gritty distortion I've heard is from Orange, but their cleans aren't great. (Not that you wanted cleans anyways) Orange is also gonna cost you more though, but their tiny terror tube amp is a great way to go.
You really need to take your guitar into a shop and spend a half-a-day playing every amp you can.
In and of itself, the Strat doesn't speak crunch to me. Designed in 1954, 3 single coil pick-ups, it's more known for it's clean "twangy" sound. Run through a distortion/overdrive .... then you get some crunch.
If you have a favorite guitar player ... copy his rig (as close as you can).
Get a Line 6 pod, and your options become "almost" unlimited.
If you really want a Marshall ... then you also have to figure out ... how much power do you need .... and are you going for combo, half stack, or full.
The Blues Jr. is a kick ass amp for the money and very portable. So are the Hot Rod series, though the old ones had som reliability issues.
This is a question on a drum forum where I actually have some knowledge. lol
You`d have to be a bit more spesific in regards to tone, budget and how much volume you need or don`t need. (and how much you`re willing to carry)
My own "Marshall" is a Suhr Handwired Michael Landau model. Great refined "plexi" tone. It`s big though, and to most gigs I bring and old BF Pro Reverb.
If you want a standard 100 watt head then JCM 800s are great. If you want more versatility then JCM 2000 might fit the bill. Stay away from 900s, no, run away from them, They suck big time. There are however many new great companies out there. One I definely would check out would be Fargen amps. Top notch stuff at a very reasonable price.
Seems a bit vague to me. You want a marshall for a crunch/gritty sound. What is your budget? What environment do you want to play this amp in? Do you just want a distortion sound or do you want multi channels?
I don't know whether to suggest a JCM 2000 TSL with 8x12" speakers or an MG10.
Like with drums go out and play some stuff and find what you like. "Crunch" is subjective. Marshall Crunch, Mesa Crunch, and Peavey 5150 Crunch are three completely different things and that doesn't even get into Bogner, Orange, Badcat etc... That being said Fender Strats aren't known for crunch either, usually one needs Humbuckers to get the classic crunchy distorted sound.
My Crunch is more like a growling Lion(ess). BTW....great replies. My Strat has a Humbucker and 2 single coils. I had my guitar player play it through is Marshall 2 years ago and it was bad a-$-$! I will take time and go out and listen to all the suggestions. Thank you all!!! (from a drummer....not a guitar player)