I have a 65 econo pickup with a 170, was gonna swap to a 200 as it would be easy as take one out and put ine in, but now I have a possible 250 that I can get I know there are differences but will I be able to still use the 3.03 trans, and motor mounts? room isn't a issue as I'm modifing the doghouse anyways for the oz 2v head anyways. One last thing are headers gonna be a pain to find for the 250 also. thanks