Originally Posted by cobalt327
Seen these w/your own eyes? Or anyone?
Yes, a friend had a '70 400 4 bolt main with those heads back around 1982 or so he freshened up and dropped in a customers '78 PU. Came out of a 1970 Caprice. He thought someone had had the heads off and put oversize exhaust valves in. The machine shop that did the heads told him they were factory stock and 1970 only, they did a lot of stock car engines and had done a few sets of these. Nothing to go looking for though.
To the OP, I for one appreciate you posting your experience. I'm building a 355 for my truck and will be using '187 305 Swirl Ports on it for bottom end grunt. It will be limited to 4500 by the cam so I don't need anything bigger. I just had a set of 416's given to me today. I have 2 sets of the 187's, a pair of 081's, 2 pair of the previously mentioned 416's and a set of '520 305 Vortecs. I'll be building at least one more 350 with 305 heads.
We're not all building high RPM race engines here as someone mentioned. Some of us prefer or need our power down low. I've had personal experience with hopped up 327's using the old Power Pak heads over the years and they ran pretty darn good.