I have a set of power pack heads.  They are 1.72 intake and 1.5 ex.  Are they worth saveing and having 1.94 valves installed and gasketmatch porting the intake and exhaust and putting on a 305 that is going in my wifes 62 More Door ChevyII.  What would be betrer the stock 305 heads of the 283 heads????
Thanks
Jon  

Except for restorations where the goal is to make the vehicle identical to how it came from the show room, there is no need to select Power Pack heads. They are obsolete for modern consideration and are worth a lot to restorers. So rather than then carve them up, put them safely away or sell them. Then use a set of 305 heads on the 305, or use a set of aftermarket heads on the 305. The modern heart shaped combustion chamber is much more efficient than anything that proceeded it. Vortecs fit a 305 and the factory released a new Vortec that uses the older intake manifold bolt pattern, these are worth some 40-60 hp and better fuel economy on a 327 or 350 with no other changes, you can expect similar but smaller improvements to a 305 at 30 to 40 hp more than non Vortec heads and they cost about the same as a good rebuild on a set of old heads by the time you look at hardened seats, new valves, springs, guides, etc.

Bogie

bogies advice is right on the money. vortec absolutey rock for a near stock replacement app. listen to him you'll be happy. hint check for casting 906. (30 deg back cut for low lift flow is standard on these models. ) earlt models had a weird valve job that gm later straightened out. 906's are already equipped with the mod. hint#2 dont try to improve on factory valve job. find a decent set and roll with 'em! good luck!