How difficult is it to replace an Automatic Transmission with a Manual?

I'm looking to do a restoration on a late sixties early seventies muscle car, specifically a Dodge Charger, Chevrolet Chevelle SS, Chevrolet Camaro, Pontiac GTO, or Ford Mustang. Problem is the majority of the cars I find are automatics and I'm looking for a manual. Thus how difficult would it be to remove the stock automatic transmission and put in a manual transmission? Could I use a new transmission or would I have to find one to remove from another car of similar vintage?|||That is more trouble than it's worth unless you have a complete shop, and then it's more trouble than it's worth still. Start with a manual if that's what you want in the end.|||I was about to say it is impractical, because we see this question asked about late model cars all the time. In a car of that era it is practical if you can locate the parts you need. If you had a wrecked one that was a manual and a working one that was an automatic it is very straightforward, but finding things like the pedal assembly will be a challenge. Not impossible or technically difficult, but lots of searching. When you find a car to restore join a forum for that car before you pay the money - the experience available is priceless.|||Curious - why?





With the onset of the high-powered engines in the "Muscle cars" the 3 and 4 speeds and their clutches did not hold up well.





The automatic was and is a great invention. The auto will beat a manual off the line and most, if not the entire 1/4 mile, due to automatic transmission torque multiplication.





Check out the most powerful dragsters - they have automatics.|||Depends on car you choose to do, but if your going to do any type of decent restore on an older car I would guess you would be pulling the motor and tranny anyhow. Most are not too bad to change over once you find the existing parts needed (linkages, pedal assemblies, mounts, ect), but much has to do with shifter lining up also so that is a point of concern. If me I would just keep looking for what you want instead of trying to make what you want.