Claymore: Welcome!! The choice will have to be yours in the end. But, heres my thoughts. 1. 350 4/speed thats scary, thinking problay been wound to tight, tires smoking, shifted hard you are problay right in the rebuild. Cost Money.
You said you like the L6's 250 a good motor sounds as the project has some cost restraints, but you are headed in right direction. Don't get me wrong I love the 350's they are my favorite motor so much can be done with them. The front clip is good if you have time and knowledge, i left mine straight with (soon) power disc add on.
Trip to Alaska sounds interesting also?? popcorn The Truth is Out There (Good luck keep us posted)