Im looking at a 3.5 liter engine i found on craigslist and i know a lot of the externals will change over to a 3.9, but what about internals? i imagine the valvetrain stays the same, and the pistons are the same bore size, but are the crankshafts varying sizes and what about the connecting rods?

*EDIT*

So i went ahead and bought this engine for only $125 and tore it competely down that night. Below is a list of compatible parts between 3500 and 3900

-Block
-Pistons and Rings
-Timing Cover
-Front Coolant Jacket
-Heater Pipe
-Front Torque Mounts and Brackets
-Exhaust Manifolds and shields
-Heads and Valvetrain
-Lower Intake Manifold
-Valve Covers
-MOST hardware


The only things I found 100% incompatible were the connecting rods and the crankshaft, due to the 1/3" smaller stroke on the 3500. Hopefully this info is useful to anyone who needs some spare parts and wonders if they are interchangable.