Rebuild 915 heads or go aluminum?

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gunters96lt1

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Hey guys, got a few questions.

I recently stuck a 440/727 into my Duster. It runs and drives good, just doesn't have the power I thought it would. I am almost certain its a later year block, and I will verify when I get home tonight. With that being said I think its probably low compression motor. I am going to check cranking compression and leakdown test tonight as well.

After some digging around I found that the 915 casting heads are the most desirable stock head at least if you want to bring up the CR. Talked with my dad and just so happens he has a set. They will need to be gone through and freshened up.

My question is, is it worth the $$$ to rebuild the 915's or go aluminum now? Also should note that I am going to put together a good bottomend from parts we have around. 67 or 68 block, couple different crankshafts to choose from, good rods(cant remember brand) and have some KB10:1 pistons and have some speedpro (I think) 11:1 pistons. Would be buying a camshaft that will work with whatever we decide to build.

Any advice would be greatly appreciated!
 
pound for pound - and I mean that literally - if you have the $$, go aluminum... even if you could get the exact same performance #'s out of both, the 915's are heavier - and we all know the formula for going faster
 
ScampMike said:
pound for pound - and I mean that literally - if you have the $$, go aluminum... even if you could get the exact same performance #'s out of both, the 915's are heavier - and we all know the formula for going faster
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Totally agree. I guess my issue is, it will be a while before I finish the other motor and ill want to get the best set of cylinder heads for my build.

I guess I was kind of thinking depending on cost of freshening up the 915s I could run those on my low compression 440 that's in the car.
 
After your iron heads are cleaned, checked for cracks, valve job, decked, new springs, locks, and retainers, you are right at the price for the entry level aluminum heads. Sidewinders or stealth hears are right at around 900 bucks.
 
or you can spend a few bucks more and Buy a good head. Buy them once. I have OTTB Eddy Rpm Performer heads on my big block, very good quality and they make good power. Have seen many cheap offshore heads that are just that cheap, and they make no power on the dyno....
 
The costs are reasonably close, but you will spend more than iron to put aluminum on it. Nothing is good enough for me to run out of the box. The lesser lines of heads need parts and the valve job fixed. The RPMs just need the valve job fixed and the springs replaced if the cam warrants it. The cheapest aluminum will run you about 20% more than well done iron.
If it was me, I'd leave the heads you have. If it needs a little more steam stick some bolt ons into it until you can build what you want. Just me though.
 
Last time I had a set of iron heads rebuilt it cost me about $1500. After that I decided to switch to aluminum and I haven't ever gone back to iron.
 
Thanks for the replies guys! Still undecided on what I want to do. I think I might wait until I put something together and buy heads for that setup. I have a plate kit on it, so that will probably get me by haha.
 
I once had some iron heads rebuilt and they were junk for $900.00 - One thing to think about do you know for sure if the heads have been milled if so how much going through the same thing right now and going aluminum that way I know for sure
 
Aluminum are still a bit pricy compared to iron and sometimes there are no
real gains for stock or mild performance builds.
 
My machinist quoted me $800 after they were checked out to be good builder heads. I'm glad he didn't charge me for checking out 2 sets of heads just to find a set of good ones.

I am in your shoes with the heads allready. So there was no extra cost in getting the heads.

But I still needed valves. More money on top of it all. Just not worth the cost vs. performance factor for the build at hand.

If it was a stock rebuild for a resto car, that would be one thing. Not part of my plan.
 
If you can't do the work yourself, iron heads are just not worth the $ for performance. Not with Sidewinder, Source, Eddie stuff available at the $ it's going for. S/F....Ken M
 
Here is some thing to chew on................. From "Car Craft" July 2012

A 400 cube Mopar "B" by Brian Haflinger of IMM.

Started with a pair of E-Bay 906 heads that were complete for $125.00, milled the heads for $120.00, 3 angle valve job for $160. They kept the stock 2.07 intake and 1.74 exhaust valves.

My math says they spent $405.00 complete on the heads..........a long cry from $900.00 to $1500.00. The little "B" churned out 426hp on the pump, nothing there to be ashamed of.

915's are, as an iron head desirable, close chamber, descent ports, they can make power. If you wish more performance, up size the valves, you will/should be still much less than aluminum, unless your machinist looks upon you as the major contributor to his retirement account. As already stated, most aluminum heads bought need some kind of help out of the box; up grading is not "just a few dollars more".

What ever you do, good luck!!
 
Cost depends on what you start with and what level of performance you want. Personally I've never gotten lucky enough to get a used set of head that didn't need more than a valve job...lol
 
As stated before somewhat the same boat and have decided to go with the Sidewinder heads for around $1250 out the door what I like about them over the Stealth is that they are smooth and not cast finish - valves ground in house - springs to match your cam - angled plugs this you need to pay attention to I'm using Schumaker headers and these work with both straight and angled plugs but he says better with angled I know some headers have to be straight
 
Awesome thanks again for the reply's guys! Still undecided. Might take them to a shop and see what they think and go from there.

I know my dad worked them over years and years ago when they were on his 68 charger. Im afraid they will need to much work. I will say the ebay prices on these casting heads are outrageous !!
 
gunters96lt1 said:
Awesome thanks again for the reply's guys! Still undecided. Might take them to a shop and see what they think and go from there.

I know my dad worked them over years and years ago when they were on his 68 charger. Im afraid they will need to much work. I will say the ebay prices on these casting heads are outrageous !!
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Sell them!!!!.........As I said they are a desirable head; one year only. Some one doing a restoration might be glad to have them...........then you could go aluminum, have a fair portion of the cost covered by the sale of the 915's.

It's a thought...........
 
I'm in a similar situation. I already have a set of 915 heads with larger valves, ported and flowed. I'm wondering what performance gain I would see if I went with some out of the box aluminum heads.
 
Lots of different heads come outta different boxes.
 
JBurch said:
Sell them!!!!.........As I said they are a desirable head; one year only. Some one doing a restoration might be glad to have them...........then you could go aluminum, have a fair portion of the cost covered by the sale of the 915's.

It's a thought...........
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Theyre my dads. And he doesn't sell anything Mopar haha. So unfortunately for me no money to be made. Its a good thought tho!
 
ALUMINUM! Spent 1k on my Stealth heads (stock shape/appearance), they are much lighter than stock (like 60 lbs) they flow waaaaay better out the box, have smaller chambers, etc... We had them looked over and squared up for like nothing...
In my opinion much more desirable than some super heavy, very needy, 1967 tech...

headers77777.jpg
 
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