They aren't early Power Packs. Power Pack heads had a triangle from 1956. They were basically the same as a 462 double hump Fuellie but used small valves for the smaller 265 and 283 engines. The single camel hump are just run of the mill low performance heads. HK GTS327 used a later version of them, small port, large chamber, small valve. Engine is probably a 2 barrel. Power Pack engines were normally 2 x 4BBL or sometimes single BBL.