You may have to get shorter pushrods. Would be nice if you knew how much they were milled. Like I said, I *think* you have to take off about .100 to get them down to 80cc considering they were originally more like 90cc. I do remember thinking about doing that at one point, taking .120" off a set of 452's for a smogger motor. But I would have needed shorter pushrods, cut down the intake flangs on the heads, then the valley pan wouldn't have wanted to fit right anymore either. Bolt holes on the intake get thrown off a bit with that much milling as well. Once you get everything matched up properly, it should run decent for what it is.