Seriously consider finding another slant 6- there's actually quite a few around yet. A nice 225 will make life sooo much easier for you.
That said, use the search function to find LOTS of info on a V8 swap- lots of things to be taken into consideration.
Here's one similar to your situation:
318\a904 swap in 65 barracuda
And welcome to the site!
Edit: If you decide to pop another slant in, don't get rid of your 170 right away; you may need various parts off of it to simplify the swap! I.E. oil pan & pickup, carb/linkages, pullies...
