I have a 2001 Impala that has a bad 3800 engine. Will a 1995 Pontiac 3100 engine fit. and/or match into the transmission. Or do i need to replace the transmission as well. Then will that match with the axles.
With enough time, money, and expertise, anything is possible. The short answer is no. You will need to locate a replacement 3.8L for your Impala. This will not be difficult to do. You have about 9 or 10 model years worth of interchange, and GM installed the 3.8L in lots of different vehicles.
Also, to be highly technical, the 3.1L was considered a Chevrolet engine regardless of what car it was installed in, and the 3.8L was considered a Buick engine regardless of what car it was installed in.
By the way, what led to the demise of the 3.8L in your Impala? Those engines are usually very hard to kill.
Keep looking for a 3800 engine. As mark said, there are a lot of these engines in many different vehicles. They are usually bulletproof as long as they have been maintained and not severely abused.
Here’s a list of cars that use the naturally aspirated 3.8L engine:
Buick Le Sabre
Buick Park Avenue
Buick Regal LS
Chevrolet Lumina LTZ
Chevrolet Monte Carlo (Z34, LT, SS)
Pontiac Grand Prix