I'd stick with the 235 you have and add some goodies...I've been to a few big old car shows, and have seen VERY FEW old trucks or cars with straight-6's, even though that's what they used to have. They all have V-8's (mis)placed in them.
I like seeing a nicely redone inliner with a bunch of performance parts, especially since they seem to be pretty scarce. Plus, it's always fun to be different!
Carl
...Oh, and did I mention you will save yourself a TON of time and/or money by sticking with the engine that already fits in your truck without modification of anything? That would play a big part for me.
