Post your full technical model number, you will find it under the seat on the chassis body. Usually begins 917.
What exactly are you trying to do that you need to lock it from turning?

I am replacing the engine and need to remove the drive pulley at the end of the crank. The model number is 917.276390. The engine is a 31H77 0605 E2. I will be replacing it with a 31H777 0297 E1, at least as soon as I can find documentation on how to wire it up. Old engine does not have a fuel pump, new one does. Will probably be asking for help with that next. ;)

A pair of channelocks on the stack pulley should do the trick. If you use the rope trick if the engine rod is intact. (Rope is fed through the spark plug hole) Seeing as though you are replacing the whole engine, you need not worry about valve position.

If the old engine is not scheduled for reuse, just feed about a foot (or more) of 3/8" diameter rope into the open spark plug hole. When you try to remove the bolt from the crankshaft, the piston will be stalled by the pile of rope in the cylinder.
I do not recommend this trick to tighten the bolt on the new engine because there is a chance of bending some parts of the valve train.
Briggs offers a flywheel holder, but I don't see buying one for one job.
Most folks will do the removing and tightening with an impact wrench.
If your old engine did not have a fuel pump, you can remove the pump from the new engine as it is not essential.
Your 917.276390 uses a gravity feed fuel system. The engine you intend to install sounds like a used engine that was taken from a chassis that had the fuel tank lower than the carb. In this application, it is the chassis location of the fuel tank that determines if a pump is needed......nothing special about your replacement engine that requires a pump.
The wiring should not be a problem. Essentially you will match the wiring scheme from the old engine to the new engine.
If there are any differences in the alternator output of the newer engine vs. the old engine, it would probably be that the newer engine could have a higher output alternator than the old engine.
Not a problem though. Your tractor has a manually engaged PTO drive for the deck, so your old engine likely has the lower output alternator. If the newer engine has the bigger alternator, just use it as is. We can get into all that later along in this project.

I wouldn't bother removing the new fuel pump, if you do you will have to plug the vacuum port in the head. I seen many craftman engines with fuel tanks above the engine that have fuel pumps. What I would do would be add a fuel cut off valve before the fuel pump. I would also write down (blueprint) diagram where each wire goes to the old engine. Unclip the wire in the old engine and clip it in the new engine connectors if they are different from the old engine. That should be about all the modifications you need to make providing the starter is the same, muffler hookup the same, and the engine mount bolts are the same size along with the pto crank center mount bolt?

Update... New engine is in. Found a leak at the crankshaft seal on new engine, but it was just a seal that wasn't seated all the way. A piece of 1.5 PVC squarely cut acted as a seal tool. A few taps later no more leak.

Sorry Moser, I had already removed the fuel pump when I read your post. Plugging port wasn't a problem though. I work on VWs in my spare time and keep a full supply of vacuum caps on hand.

Now, I need help with the wiring. It doesn't match up exactly. The new engine has what looks like a rectifier or capacitor on the wires leading to the windings in the flywheel. The old engine does not. Also, the new wiring has a loopback feed where the old engine used to hook into the wires leading to the windings. Not sure if the "rectifier" should just be bypassed or worked into exiting wiring. I have detailed pix of old and new wiring if someone is willing to take a look. I can't seem to find a way to post the pix to the forum.

Any help would be greatly appreciated. Great forum and very helpful people. This and TDIClub.com are my favorites.

Great, click the link below and read about one way to post photos. If that turns out to be not your cup o' tea, e-mail them to me and I'll post them.
I believe your new engine has a bigger alternator than your old engine. The bigger alternator will work just fine.
Lets see them pictures.

Here is a link that might be useful: picture postin' primer

Here are the pix, thanks for the instructions.

Original Engine Wiring, not connected. Orange/red wires connect to plug leading to flywheel. The grey/black in photo lead to carb selenoid on both old and new engine wiring.

{{gwi:338918}}

New engine wiring - connected to old harness plug. The two black wires at top of photo lead under flywheel. Orange/Red wires have a loopback.

{{gwi:338920}}

Wiring under cowling

{{gwi:338922}}

Additional help maybe?

http://www.gardening-tools-direct.co.uk/content/husqwm247_hwen2000_173750.pdf

Gray = Carb Solenoid
Black = Engine Kill
Red = Charging
Orange = Headlights

Still not sure best place to connect the 1 loose red lead from new engine though.

Refer to picture below.
I have marked/named the wires.
Please post a picture showing the end of the chassis harness connector with the wires emerging from it (the arrow at bottom left of photo is pointing to it). In the picture you posted, the angle hides the view of the wire positions.
Question about the "jumper connector: Was this connector used with the old engine configuration?? or did it come as part of your "new" engine?

Once I see for sure how the wires are positioned in the chassis harness connector, I will give you a short list of options for you to choose from.

{{gwi:338923}}

The Jumper Connector came with the new engine (I have no idea if it was factroy installed or not). I assume it is a loopback to feed power to the headlights. The picture of the original engine wiring shows the pigtail with the orange and red wires plugged directly into a plug leading to under flywheel.

I will get more detailed picture of the main plug posted by 5:15 Eastern time this afternoon.

At that time of day, I will be at work, so look for my response to post sometime tomorrow AM (7/14).

One more question... If there turns out to not be an optimal way to wire new engine in, couldn't I just swap the flywheel/alternator parts? Just a thought, thanks.

Yes, you can swap the flywheel and the stator from your old engine.......if, as you said, you need that option (and that was one of the options on the list).

Ok, here's the best of 4 shots i took.

Orange to pigtail Orange
Red loopback (top of photo) to pigtail red
Black/White to Engine kill
Blue and red loopback (bottom of photo) to carb solenoid
White to nothing

Note from previous pictures: orange and red pigtail is loopbacked on new engine. Used to be red and orange straight to under flywheel.
{{gwi:338924}}

Sorry for terminology in previous post, not pigtail, jumper connector.

Basically, all you need to do is splice the two wires in the jumper connector together. Cut the jumper wire in half as suggested by my photoshopped image, strip some insulation off each, and connect them together in a 10 gauge butt splice, both stripped ends of wire in the same end of butt splice. Insert an extension lead of red 10 gauge wire About 8 inches should do) in the other end of butt splice. Cover the splice with heat shrinkable tubing.
Cut off the red connector from the charge output wire on the regulator. Use a 10 gauge butt splice to connect the red regulator wire to the extension wire you added to the other 2 wires. HINT! Besure you put your heat shrink tubing onto the wire BEFORE you crimp the butt splice down.
Joining the two red wires in the jumper connector serves to provide power to the orange wire that will operate the headlights, the red wire of the jumper serves to charge the battery.

{{gwi:338925}}

Will let you know tomorrow how I make out. Thanks.

Well engine is in and running, sort of. i need to get a tachometer to set up the rpms and adjust carb. however, did get the engine running and it seems ok. Not sure about the wiring though. initially had a sticky choke and flooded engine. then had trouble getting it started and eventually wouldn't turn over. swapped starters with no improvement. eventually got it started and let it idle for a while. went to restart and it didn't have enough power to push through the compression stroke. so I've either killed the battery or it isn't charging. will put it on the battery charger overnight and let you know how it goes.

At least I've made progress. I know the new (used) engine runs good.

Hey Mownie! I think we're good! She seems to be charging just fine. Still a bit of trouble overcoming compression stroke on start, but she will start. I adjusted the valves to .006 Exhaust and .005 Intake 1/4" ATDC. Seemed to help a bit, but not completely. At 1 point I had valves way too tight. She would spin right around great, but tight valves not a good thing. Maybe I will go to .005 and .003 when I recheck valve adjustment. Any who, knock wood, I think she's all set. THANKS A BUNCH FOR ALL THE HELP!!!

I think I'm going to see about rebuilding the old engine and keep it as a spare. Wish me luck and thanks again.

Great news on a successful project.
Set your valves at .004" intake and .006" exhaust. Yes, it makes that much difference.
And.........good luck on your engine rebuild project.