Chevrolet Repair: 3.1 to 3.8 swap, wrecking yard, lumina

Question
I am looking into swapping a 3.8 series 1 from a 1990 lesabre into a 1995 lumina which currently has a 3.1.  I have the entire lesabre on site and there is nothing wrong with the drivetrain, but the rest of the car is rotting away.  The lumina engine has a very bad top end rapping.  I understand this is not a simple project.  My inquiries are;
What difference is there between the block castings for the different body styles if any?
What will differ between mounts?
Would I need to use the axles from the lumina to retain proper wheelbase geometry?
Where are the parts normally available to do the swap?
Did I miss any obvious major problems?


Answer
Hi Jeremy...you are looking at a huge task....you would be better to switch from a 3.1 to a 3.1... you will have to change everything, the quickest way to see what you need to do as far as axels go is to check with a wrecking yard that has an interchange book... it will have a list of engines that interchange with that 3.1 and what all you have to swap over....as far as i know you would have to chenge the engine trans wiring computer all sensors and switches have to match sensors to gauges /or lights.... huge task.... hope this helps