If your doing a stock rebuild you should be able to do it yourself with some help from your bud. Machine work and a rebuild kit should come in under that $1500 for a rebuild. I'll agree to what others said on the different factory rebuilds out there. They mix and match and use what they have. Your stuff should be in pretty good shape hopefully plus if it's the original engine you want to keep it anyway. 64 used the lowriser heads. Most of todays rebuilds you find come with C8-H or D2-AA heads. Some of these might not have the vertcial exhaust pattern you need. They could be drilled and tapped tho. But that's another thing to think of also and potential headaches. There are many people that can help you along the way. I'm still learning new tricks all the time. Take your time and plan a nice build in advance that suits your budget. We can help you spend it....LOL

G.