I have 3 sets of type 4 heads available to suit different applications . Thease are all from the US and are ported on the intake side and welded and ported to a late square port exhaust . All have stainless valves from 46 x 40 to 43 x 38 and new guides . Springs are vw duals and the chambers range from 52cc to 70 cc . I have them to suit larger 103mm and 105mm only and are priced from $ 800 a pr . These are in Wolongong NSW and matched idf manifolds are also available , ROD , 02-42729920 .