I have a rebuilt 306 with a B303 cam and 1970 351 heads with bigger valves. They have been pocket ported and exhaust ported and I was told they should yeild around a 9.5:1 compression with it's 58cc chambers and a regular .031 comrpessed head gasket on a flat top piston. The motor now has 200 miles on it and it is a dog. What should the timing be set at with this cam? The original stock motor had a lot more balls than this car. Any help would be appreciated.Thanks.