8.8 swap

Ya get what ya pay for, I know, but I'm thinking about going the exact same route. I'm building a 1966 Barracuda, going for a kind of SCCA, road rally look and feel. I'm pricing 8 3/4 rears, fully aware my Dad built a 1965 Dart Gasser and with a few modifications to the perches and such, he was able to use a Ford 8.8 rear out of a Ford Explorer Sport. Thinking about biting the bullet and going pure Mopar (8 3/4 can be pricey) or going the same route my Dad did. I have found 8.8 rears as cheap as $130. I'm not building a SEMA car or anything like that, and am not worried about numbers matching, either. I'm dumping the tired 273 and putting a rather healthy 318 in it so I want to stay away from the 3.25 rear. I've found some ads that say "Limited Slip" and others that say "Open Differential" and I'm not quite sure which one would be equivalent to Posi. I'm going to get with the old man before I buy, but are there any other suggestions or input?