I want to put a Chevy 350 motor in my 2006 Camry. How long will it take me to cut out all of the firewall?

Big waste of time. You do know your car is front wheel drive, don't you?

You'd have to completely rebuild the chassis to hold a rear axle / suspension, etc.

The V8 will not fit / would be too heavy, etc. How do you plan to support the weight of this engine?

well you should only cut out what you need, and plan on boxing the frame and reinforcing the entire frame as best you can, The idea being to strenghten the frame to hold up inder the extra stress a heavy powerful motor will add to it. this can be as simple as cutting a triangle shaped piece of steel on a corner of the frame (look up what boxing the frame means in your internet search box. If you have a die grinder it should make quick work of the firewall, you want to add extra strenght there too, that is also part of the structural support of the vehicle, so make a steel frame around the section you cut to add strength. have fun.and plan on

what kind of tolls you got a grinder will do it real quick or a saws all will do a great job both of these tools will work as quick as you do so it will not take as long as you think but make sure you got plent of baldes or stones for the grinder ok 1 hour or less if you eng is pulled already

Better raise that camry up and 4x4 it, cause it aint gonna fit.

15 minutes with a plasma cutter.