340 X heads advice

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barracudadave67

barracudadave67

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Im going to look at a pair of "bare" 340 X heads on Tuesday 4/9/19. What should I look for as far as problems, I not a engine guy, so I could use some advice.
I have a early 360 short block that I want to put together for my 66 B-Cuda. I bought it minus the heads. Guy kept them.
I can get a set of 3769973 heads cheap, don't know what size valves are in the 973s. I know this block had J, or X heads on it, before I bought, so I think the X heads would be the way to go.
I also have the A-904 that was hitched to the 360 block. I will turn an already installed 8 1/4 rear.
Thanks in advance
Dave
 
Look at the valve seats. If they are really wide or wide on one side and narrow on the other, buy aluminum. That means they need guides and seats. The guides wear and the valves flop around beatin the seats to death. Guides and seats alone are worth buying new heads for. Being bare, you're already out valves, springs, retainers and valve keepers. That stuff adds up. Me? I wouldn't even go give them a look.
 
Exactly what he said, but if you are on too little budget for aluminum, the iron engine quest magnums may be worth a look.
 
If they are not 202 valves, then X or not really doesn't matter from what I've been told. In fact I have a set of J heads that are 202
 
Dependent on machine shop you are using will depend on cost. If heads are used plan on valves, guides and new seats no matter what so when the machine shops quotes you.... you are not surprised.

As for what to look for - bring a good straight edge and feeler gauges and check for warpage on head gasket surface. If you don’t know what I am talking about then google that plenty of videos online. Also look for cracks between the valve seats or seat edge going outwards.
Check spark plug threads. Look for the area around the bolt head mounting faces for dug up or gouging- over tight. Over all look at the heads- lots of coats of paint mean possibly they have been on multiple engines. “X” heads are not as hot now as they used to be because of the amount of good new heads available now. A good budget for heads for stock should be about &1500-$1700. Including cost of heads. So I’m not sure what you are spending keep that as part of the equation- remember cylinder head work can be as expensive as you want it to be. Good luck!
 
We really can't tell how much they have been milled by just looking. There is a point where shims under rocker shafts are required.
 
If it were me I would look at buying some EQ heads bare and have them set up the way you want them or look at IMM engines website. They have them ready to go with 202 valves. They are a better flowing head than any stock passenger car head also.

IMMENGINES.COM
 
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It's the diff between 500-600 to reman the x heads and about 1500 hundred for new.
I've 'clean up' milled mine 3 times, they were still only 69cc

If the OP isnt doing much over 400 hp ...what's the point of after market?
 
Leave the "x" heads for the restoration crowd the IMM heads aren't a bad deal but for a little more you can get a pair of Edelbrocks..
 
If they are the bare ones on CL from Racine, I asked about them a week ago and he really couldn't tell me anything about them. They've been ported but no numbers. Didn't know if they have been surfaced. Seats look a little tough in the poor picture. I would consider them needing full rebuild. Guides, valve job, and light surface cut at minimum. I don't know how much the machine work would cost but you could ask Kilpatrick Auto in Waukesha. He speaks Mopar. You will also need several hundred bucks worth of valves, springs, and guides and maybe spring seat work depending on your springs. The asking price isn't bad but if you have to put another 6-800 in them I would go with the IMM option or one of the aluminum versions avialable. I passed mainly because I have no idea if the porting is good or not.
 
abodyjoe said:
exactly.. some guys thing they are gold still but thats not the case.
Click to expand...

So true I have several sets, they are still a good head if you already have them.
My current build I am using "J" heads on a 318, why because I also have a few sets of them.

There is a machine shop in Charleston WV that just went thru the set of "J" heads that I am using.
His prices are reasonable he charged me the following:
I provided new springs and valve seals.
$150 for a 5 angle valve job, and to clean and assemble the heads.
$25 to mag the heads
$100 to give them a slight mill for flatness.

So machine shop prices can be all over the place, you have to shop around, he is two hours drive one way for me, but the local shop, which is 10 minutes from my house, their prices are basically bend over and take it.
 
It has been a while since I had any machine work done, but in my area I bet you would have right around $1k in those heads to do a total rebuild with good parts, ready to bolt on and go, not including cost of the heads themselves, and that is if they are still good and able to be rebuilt.
 
gzig5 said:
If they are the bare ones on CL from Racine, I asked about them a week ago and he really couldn't tell me anything about them. They've been ported but no numbers. Didn't know if they have been surfaced. Seats look a little tough in the poor picture. I would consider them needing full rebuild. Guides, valve job, and light surface cut at minimum. I don't know how much the machine work would cost but you could ask Kilpatrick Auto in Waukesha. He speaks Mopar. You will also need several hundred bucks worth of valves, springs, and guides and maybe spring seat work depending on your springs. The asking price isn't bad but if you have to put another 6-800 in them I would go with the IMM option or one of the aluminum versions avialable. I passed mainly because I have no idea if the porting is good or not.
Click to expand...
The part about them ported and with no numbers is the 'sketchy' in the deal.

IF they weren't in that way... valves are only around $90 a set "16" for some Elgin pro stock 2.02/1.60 11/32 +.100...as good or better imo than edelbrock valves...though I put them in a lathe and 500 grit on the backside and stem.
$80-$100 a head to grind seats/face valves, $50 a head for guides, $45-60 to mill/surface, $25-$40 mag... springs $47-$120 depending on what cam...$16-$24 a set for locks....reuse retainers or 54 a set ...and go with the comp super stuff.
OP, do whatever you want, Im just putting the info out there for you and others. I'm not trying to spend your money.
 
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barracudadave67 said:
Im going to look at a pair of "bare" 340 X heads on Tuesday 4/9/19. What should I look for as far as problems, I not a engine guy, so I could use some advice.
I have a early 360 short block that I want to put together for my 66 B-Cuda. I bought it minus the heads. Guy kept them.
I can get a set of 3769973 heads cheap, don't know what size valves are in the 973s. I know this block had J, or X heads on it, before I bought, so I think the X heads would be the way to go.
I also have the A-904 that was hitched to the 360 block. I will turn an already installed 8 1/4 rear.
Thanks in advance
Dave
Click to expand...

You didn't say what price you could get them for, I wouldn't pay over $200.00 for bare castings ...........that said buy them and resell them to some one who desperately needs/wants them. Then take the money and buy a better set of heads. There are 3 kinds of people who want "X" heads, restorers, class racers, people who think "X's" are the be all, end all of small block heads. Any small block head with a 1.88 intake valve will become an "X" head equivalent with the addition of 2.02 intake valves. You have stated the "X" heads are bare, so you have to buy valves anyhow, just buy a set of 2.02's and have them installed, springs to match cam, knurl guides if they are loose.
 
I knurl and finish the guides even when they are not loose- even new ones- they oil better and last longer
I think I still have several sets of J and X heads PT and Mag,with durabond exhaust seats milled for end to end = ccs
cant get my costs out of them
 
894 X's are only good for the resto folks that have to have them and should not be bought only for the letter. You can find a ton of 915 J heads for cheap and start from there, same basic head. I'd prefer a 1.88 head to start with if wanting 2.02's for the clean high and proud seat cut you can get on them. No sunk seats like a lot of the older factory 2.02 stuff.

I would not pay a premium for them. Bare... you're going to have a bunch of money in them by the time you are done.
 
OP, we have no idea what you are doing with this engine and heads, your rear gearing, nor what is in the 360 block for pistons. If these are stock, low compression 360 pistons and you want to put a moderate to large cam in it with X-heads, you will have an engine that will tend to bog at low RPM's. If this is not a race or strip application, you may not be happy. In that case, you may be a lot happier IMHO with a set of EQ heads with the smaller chambers.

So some more info on the application is needed to help you along.
 
Having recently done a set of EQ heads for my 360 build I have no idea why you would even look at X,J or any other old heads. With nothing more than 2.02s and a valve job they kill decently ported LA heads.
 
67autocross said:
Having recently done a set of EQ heads for my 360 build I have no idea why you would even look at X,J or any other old heads. With nothing more than 2.02s and a valve job they kill decently ported LA heads.
Click to expand...

Can I ask where you ended up buying the EQ's from?
 
gtsdude said:
Can I ask where you ended up buying the EQ's from?
Click to expand...
I just ordered them through my local machine shop. I buy anything I can through them and in turn they treat me great. A few weeks ago the owner let me into the shop on a Saturday and he showed me how to port those EQ heads. He even flowed the heads before and after for me... I posted the flow numbers in my build thread
 
upload_2019-4-9_14-7-34.jpeg
 
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