I know I will need to replace the rod bolts in my build, but do I need to replace my head and main cap bolts? Thanks.  

Replacing the heads bolts is usually a good idea if they have seen a lot of stress cycles. Also, if there is any pitting on the threads or any damage at all it will cost you some clamping force, it may not be much but it's more a guessing game with reusing 30 year old pieces...

I usually stud the mains in many high performance builds so the main bolts are usually replaced. The studs also make it easier to install a windage tray, which controlling windage is always a great way to gain top-end horsepower and especially power past peak.