3 mechanical questions

I have 3 questions

I want to buy a '91 dodge daytona es (3.0L V6) and it needs a water-pump (internal), timing belt, crossover exhaust pipe gasket. I also want to replace the cam and crank oil seals, and replace the valve stem seals. I have no experience fixing cars, but i am quite determined to do it myself, and i was wondering about how long a person like me would take to complete this project.

Is a torque wrench neccesary when certain bolts need to be tightened so much?

How do you make a camshaft holding wrench?

Thanks

I like your goal, but I would start with something more manageable. Perhaps a car that has an external water pump, or one that just needs a set of plugs. These repairs you mention are critical and if ANY mistakes are made then you could blow a motor. I would bet that this would be the outcome unless you have someone with experience to help you.

If you must proceed, here are a few suggestions:
1: Get a haynes or Chilton Manual for this car.
2: Valve stem seals can be tricky for a novice unless the heads are removed.
3: The timing belt is fairly straight forward.
4: Do you need to rotate the cam? Just put the pully on the end finger tight and use a strap wrench if needed.
5: Please consider learning engine basic operating principals on a smaller/cheaper engine. Like a old lawnmower motor. You can learn how the parts must interact in timing, ignition, and fuel. This is good because if you screw it up you can rebuild it in an hour or so and it will not cost much or leave you stranded. If you work on your car motor and then you AND your friends get stuck somewhere you won't hear the end of it. We are always here if you do go ahead, but a lot of mechanics is done by feel and little details(like the direction to turn a nut) become instinct that we may forget to mention. This could cause you a lot of problems.

With agreeing with public, wiith machining included it should talk about 5 days if you're motivated enough. You're going to have to take the whole motor out, remove the head to have the valve stems replaced, change the seals and put it all back together. I would definetely recommend you seek help from an experienced person for this matter. If you are removing the head, yes, you need a torque wrench to re-assemble. More than likely if you are replacing the head and main seals(among the other things that you've listed) you are going to need the following:
Head Gasket
Valve Cover Gasket
Rear Main Seal
Front Main Seal
Oil Pan Gasket
Hi Temp RTV
Water Pump Gasket
Cam Bearings
Timing Belt
Exhaust pipe Gasket

If you were to replace the cam, you should also take on new cam bearings, i retake my first estimate of 5 days and move it to a week from lack of experience. This is if you're completely dedicated to the task, it could take you a lot longer as well...

(P.S. I've acutaully changed the head gasket on an 89 shelby daytona in about 3 hours, it can be done, its just how focused you are on the project)

Well from what other experiences i've read, all of it can be done with the engine still in the car, the only problem would be working with the rear valve stems cause they are up against the firewall. The timing belt whatnot can be done if i remove the right splash shield and work from there. I just wanted to know what I'm getting myself into. I love those daytonas

You said you want to replace the crank seals? There are two, the front main and rear main, to access the front you need to remove the main pulley, to access the rear you need to disconnect the transmission. You're going to need to remove the oil pan as well (requiring a new pan gasket).

oh thanks for the info, i had no idea there were two. Well my intention was to do the crank seal on the timing belt and the cam seals as a precautionary step for it not to leak (it's prone to it, but usually from the valve stem seals)