WIW X-Heads

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if you go eddy make sure you get them checked out. know guys find tight guides most of the time. heard of a few bad valve jobs too..
 
Both RHS and Edelbrock are closed chamber heads (Edelbrock does make and open chamber head to work with above deck pistons). The X heads are not closed chamber they are open to deal with the pop up pistons used on those early motors that the heads came on.
 
My issue with used heads is the unknown. It's difficult to tell if they have been milled.
During a 40 year lifespan they may have been milled .03 only once or .02 three times.
Milling the heads screws with pushrod to rocker geometry. Then you'll need shims under the rocker shafts. Fun aint it ?
Good luck with whatever you choose
 
X heads are an open chamber head; to achieve your goal of 400 to 430hp is gonna require port work, not a lot but some.

Go back in the "Mopar Muscle" archives about 12 to 14 years, Dulitch built a 360, he ported the heads (587 castings I think), with a Comp Magnum 280 cam he dynoed out around 430hp; in the zone you hope to be. It would be good reference materiel to help you get where you want to go.

What ever you do, good luck.
 
For $200 I would pick up the X heads even if you dont use it, you can always resell later.
I have both X heads and eldebrocks on two different small blocks.
The X heads were machine shop fresh for $500.
The eldebrocks were for my magnum they run me $1550.
 
sireland67 said:
For $200 I would pick up the X heads even if you dont use it, you can always resell later./QUOTE]

My exact thoughts....For $200 I would pick them up.
Just go to ebay and look at what people are asking for them.
Just like an A body 8 3/4,X heads are getting pricey.
Click to expand...
 
Johnny Dart said:
sireland67 said:
For $200 I would pick up the X heads even if you dont use it, you can always resell later./QUOTE]

My exact thoughts....For $200 I would pick them up.
Just go to ebay and look at what people are asking for them.
Just like an A body 8 3/4,X heads are getting pricey.
Click to expand...

Don't forget that what they ask for, doesn't mean that's what they sell for.
Click to expand...
 
Wow...Thanks for all the responses guys! I'm going to go ahead and pick up the X-Heads. From what you're saying, I can't go wrong price wise. Even if I just sell them down the road, at least I know I won't be losing money. As far as which head to run.....Still kinda stirring on that. Leaning towards the Eddy's. I'll probably Magnaflux the X-heads myself (have all the equipment) and then drop the X-Heads off at a local guy that does a lot of cylinder work, and have him give a look over. At least then i'll really know where I stand. Maybe pick his brain on a ball park for the work. I was hoping they were closed chambered for quench...another plus for the eddy's or RHS.


Anyways, thanks again! Didn't want to get the cart before the horse so I picked this up today:

dede_zpsff3df096.jpg



'71 340 and forged crank.......
 
JBurch said:
X heads are an open chamber head; to achieve your goal of 400 to 430hp is gonna require port work, not a lot but some.

Go back in the "Mopar Muscle" archives about 12 to 14 years, Dulitch built a 360, he ported the heads (587 castings I think), with a Comp Magnum 280 cam he dynoed out around 430hp; in the zone you hope to be. It would be good reference materiel to help you get where you want to go.

What ever you do, good luck.
Click to expand...

Here's the article:

http://www.moparmusclemagazine.com/techarticles/engine/mopp_0211_340_x_head_buildup/viewall.html

This ^^^ is why I kept my iron heads and reworked them over. machine work expense has been kept to a minimum due to a colleague having a seat and guide machine but I still had to send out to be resurfaced. total machine work $200, total in springs, retainers, keepers, guides, seat inserts, and valves: $500. I got a lot of good deals on new stuff here on the forum and surprisingly, Rockauto.
 
71Scamper said:
Here's the article:

http://www.moparmusclemagazine.com/techarticles/engine/mopp_0211_340_x_head_buildup/viewall.html
Click to expand...

If that 280 magnum cammed made a real 400hp, I'd be surprised. Dyno's can spit out all sorts of numbers, numbers sell parts and magazines. None or few of those engines usually ever end up in a car to prove out the claims.

The bigger MM lobed one would make in the 400 range. That's a pretty aggressive lobe family and not really easy on valvetrain from what I recall.

I've been involved and built a few of those xe268 cammed mills that the mag build started with. NONE ever made 390+hp... more like 335-350 depending if a 340 or 360 inch engine. Proved to be the power HP point when run at the track for MPH/wt.
 
crackedback said:
If that 280 magnum cammed made a real 400hp, I'd be surprised. Dyno's can spit out all sorts of numbers, numbers sell parts and magazines. None or few of those engines usually ever end up in a car to prove out the claims.

The bigger MM lobed one would make in the 400 range. That's a pretty aggressive lobe family and not really easy on valvetrain from what I recall.

I've been involved and built a few of those xe268 cammed mills that the mag build started with. NONE ever made 390+hp... more like 335-350 depending if a 340 or 360 inch engine. Proved to be the power HP point when run at the track for MPH/wt.
Click to expand...

well I guess I'll be the one to do some actual dyno time to prove out the numbers. the only difference between my build and theirs is the cam. I'm running a voodoo hydraulic roller setup with very similar specs except on a 112 lsa instead of 110
 
71Scamper said:
well I guess I'll be the one to do some actual dyno time to prove out the numbers. the only difference between my build and theirs is the cam. I'm running a voodoo hydraulic roller setup with very similar specs except on a 112 lsa instead of 110
Click to expand...

Hyd Roller is not even close when comparing the .050 numbers, etc. It's not an apples to apples deal.

I built an engine with a hyd roller that surprised everyone that was involved! It Idles like grannies stock 318 valiant!
 
looks like you got start in the back of that truck I'd love to see the build up on it "x" heads or eddy's
 
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