[DAVID GAGNARD]

If Craig's estimate of a 40hp increase (and I have no reason to not believe him),then IMHO they are not worth it if you already have the iron heads.....For instance, I have the same iron heads that you have when building my motor.... Being a scrounger and having access to a machine shop does help.... Got my heads milled and tapped for screw in studs---free,did the valve job myself-free,traded out some work with a buddy who spent approx. 24 hours of work porting-polishing-bowl blending and gasket matching the heads,again free,traded out some body work to him on his late model mustang....

Had to pay a shop to put in new valve guides,do not remember but it was not that much.... Machinist was looking over the heads and said the work was top quality,but said with all that work I probably would only gain 40 to 50 hp....I was floored,did not think it would be that good... He has a lot of expirience with dirt track motors and dynos and has done a lot of expirementing with heads and intakes so I trust his judgement.....

My point is,the old iron heads can be made to work rather well when reworked,if you had to pay or source out all the work it would not be cost effective,new aluminum heads would actually be cheaper,but if you horse trade and can do some of the work yourself,you can build a really good set of heads fairly inexpensively.....Around here the C-9 and D0 heads can be bought for as little as 50 bucks per PAIR.... I have three or four sets in my shop that have been there for 10 years or more and would gladly let someone have them for 50 bucks a pair,take your pick. I really do not need them and they are just taking up space....

For a street car, anice set of iron heads will be more than adequate for your car,serouis racing would be different....
Again,just my .02 cents on the subject....

David