Thanks for the comments guys and I will weigh this matter some more. I just don't want to invest more new parts into the 340 if I decide to go with the 440. I also don't want to waste the 6-pak carb set up. I have a friend who will sell me a 70 440 for the GTX. I am putting the GTX back as close to original as possible. The Challenger will be doing street duty. The GTX, the show scene. I have to pull the 340 to put a rear main in, I plan to put new headers and exhaust. That is if I stay with the 340. This would also be a good time to drop the 440 in and add new headers. So that is where I'm at.