No,not the bump that the valve runs through. The newer heads in question have a bump that hangs down from the top of the exhaust port,a rather large intrusion actually. You grind that bump down smooth. It has to do with emmissions.
Grind the emmissions bump out,it doesn`t need to be there and will do you you no good if you leave it alone. Just grind it down smooth to match the contour of the exhaust port.
I rebuild engines and have for a long time . You can find some good heads from 1969 & 70 after that they went down hill . If you are just having fin on the street a goo set of GT40 heads are good that are on the GT Mustangs . Ford re-did the angle of the spark plug which from the angle plugs that are aimed at the exhaust valve and are worthless for performance . If you really want performance heads and good flow , just save yourself all the headaches looking for good heads that you will pay $300 and up for then spend a machinist to do the valve job , new bigger valve in the head , porting and so on so by the time you get the bill just go and spend $1000 for a decent set of alum aftermarket heads that will give you the flow and performance you want . It's much easier that way and you won't really spend that much more than having another set of heads redone the right way . Keep an eye out on C/L . You can get some damn good deals on there from $500 to $700 for a great set of heads . I just saw a set of Sr. cast heads for $700 and have seen them for less before and they are great flowing heads . Used Edelbrock performer heads for $750 . It really doesn't pay to have the work done on a heavy cast iron heads when you can get alum heads that are lighter and perform much better for the same price ! Just my opinion . Retro Jim
Thats what I thought... They are ported but the ports are not huge. But specially the exhaust look a lot better than the latemodel ( E7, I think ) heads I'm using right now. The holes for the plugs are big, which would be right for the early type plugs, the combustion chambers dont look like they were worked on. From what I could find on the web they are about 60cc, which with a post '71 tall block and my second hand dished ( and forged ) TRW's should give me about 8.5:1. Just about perfect for the old Accel draw through Turbo I'm using. Does all of that sound about right?
Thanks guys, I'll grind out the emmissions bumps and smoothe the rest of the port out and I think that should be fine for what I want. Thank you to everyone that replied to my question, I really appreciate the help and will probably be calling on you again for other questions during my rebuild and engine swap..
Now that I`ve gotten past that, I have to ask about the larger (7/16th I think ) threaded holes in the end of the heads. Are they origianlly to do with the smog control, I am wondering if they hooked up to the pump in the original application. I can see that they are connected to the holes that were in the emmission bumps that I ground off. Can I just put a plug in them . Thanks
I had a stock '88 that would blow the doors off of '87-'88 350 powered iroc Camaros. For half the price even!! Them cars were dubbed "best bang for the buck" back in them days and they were!!
Yeh, you can grind the hump all the way out so the roof is flat. The heads pictured are early heads, see the 18mm plug holes.
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