i just got a free set off heads from a buddy. They are 3927186 which appear to be camel humps from a 69-70 302 or 350, im wondering if these are good heads to build up? thanks

Those are pretty good heads, but if it were me, I'd sell them and put the money toward a set of World"s S/R torquers, or maybe Dart S/S or Iron Eagles.
The 186 double hump heads are valuable to the right collector, someone with a Z/28 or vette, you might be able to get a good amount of cash for them on E-bay or somewhere.
If you decide to use them yourself, make sure to have them checked for cracks and other damage before sinking a lot of $ into them. The heads with factory 2.02" intakes in particular had a tendency to crack in the combustion chamber next to the intake valve on the chamber wall, where the factory relieved the head to unshroud the valve.
These heads also were not meant to be used with unleaded fuel, so that will have to be taken into consideration as well. Could spend some serious $ to make them right, depending on the condition they are in now.

Camel hump heads were pretty good in their day, but by today's standards they aren't so great. As for stock heads, some of the fast burn or vortec heads can be reworked for less money and perform much better. The aftermarket is full of excellent choices. For one thing, combustion chamber designs have been modified to reduce shrouding of the intake valve. Also, the chamber design and plug locations have been adjusted for improved flame front travel. The Camel hump heads lack mounting holes in the front that many accessories depend on. Blue said it best...find a collector and get some money to put toward another set.