Cracked Magnum Heads - Junk or Not?
"I'm not sure what you mean by that last sentence. Could you explain?"
These heads are iron, and limited by minimum cross section due to the pushrod pinch. They flow well - very well - for what they are. But as soon as you have to start whittling to get more air though them, the costs go up because iron takes twice as long or more to port than aluminum, you can't just hog them out and get huge numbers, and ultimately the iron heads are heavier than the aluminums. So once you have to spend more cash, the aluminums - IMO and using my local pricing anyway - are more overall cost-effective.
OK, I get it. Makes sense to me. I'll comment further below.
1wild&crazyguy We all have great points, but is he asking what head to buy or is he asking if these old heads of his can be made good to sell to someone else to run for x amount of miles?
The post title says it :) I think the question has been answered well enough. I'll put them up for sale cheap. But the conversation is informative. It's interesting to see the different perspectives. So I'll keep it going a bit...
I wanted from the beginning to go with aluminum heads. Aluminum appeals to me for the reasons stated. I decided on RHS based on these considerations:
1) I'm doing the junkyard 5.9 build. For the Eddies to make sense, seems I'd need to change the pistons for higher compression, hone etc. The pistons are not cheap.
2) I'm told the Eddies should be "gone through". This one bugs me. I suspect many are just bolted on and do fine, but the advice comes from respected folks so I don't want to ignore it. Hard for me to know what that adds to the cost.
3) Moderate performance goal (400 HP range). RHS heads should get me there with some peace of mind regarding quality.
I think if I go for much more power, I risk breaking things, especially with a 4 spd. The overall cost potentially gets out of hand.
One thing I should look at. What do the Eddies need for rockers?
I'm planning to do the Hughes shaft rocker system on the RHS heads which of course is a substantial added cost.
