225 slant 6 or 360 v8
its really up to your personal preference
powerful 360s are easy to be made and there are a ton of clear recipes around...many of them right here on the board
on the other hand, if you want to stand out, there are a lot of powerful /6s out there aswell BUT they require a bit more work
as much as I love my V8 I must admit, a blown slantie stands out in the crowd a lot more then a 360 does
and...you wont have anyone bothering you with silly "is that a 340" questions
so, option 1, quick and easy, drop a 360 in there
option 2, completely rebuilt that /6 for power, turbocharge it or whatever and have something that stands out