i have to replace the engine in my 2003 grand prix it has a 3.1 and i have found several 3.4, but no 3.1 engines. could i easily switch to the 3.4?
Check in with the people at GAOwnersClub.com - the Grand Am uses both of those V6's and they sometimes swap parts. I would think that the engines can be swapped along with the ECU but there may be modifications that I'm not aware of.
throw in a 3.8
I'd go with a 3800, get a newer L26 out of the junkyard from an 06 or newer Lucerne, Grand Prix, Lacrosse, etc. Can be had very low mileage for cheap price. Slap a new intake on with your old throttle body and it'll be bullet proof for another 300k miles.
Looking for a Used Grand Prix in your area?
CarGurus has 2,670 nationwide Grand Prix listings starting at $1,750.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts