340 X head advice

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65Valiant_NC

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I recently picked up a 340 out of a 68 Dart and tore the engine down. The block, crank, rods and heads check out fine and need very little machining. The bottom end I'm leaving it stock with the exception of a Lunati cam #10200703 (.494/.513- adv duration 268/276) but I'm torn on the heads. I don't know whether to just redo the heads with stainless valves, bronze guides and a 3 angle or do what I just mentioned with some bowl work and intake matching. I have a set of Milodon megaflow valves which came with the engine but I'm gonna have to ship the heads to get them ported. No one in NC will touch them. So to port or not to port? Is it worth it between all the shipping and what I'll gain hp wise?
 
Sell them to a numbers guy and put some aluminum heads on it.
 
If you NEED to have a numbers matching engine.....
Then use them. The max you should be bothered with is a bowl porting with good 2.02-1.60 valves and a gasket match which the gasket matching is adding very little.
 
Sell them to a numbers guy and put some aluminum heads on it.
I have thought about that
If you NEED to have a numbers matching engine.....
Then use them. The max you should be bothered with is a bowl porting with good 2.02-1.60 valves and a gasket match which the gasket matching is adding very little.
I thought about what RustyRatRod said and going with aluminum heads and it's not a numbers matching deal. My plan was to pull my 273 Commando then make the 340 look just like it with the valve covers and air cleaner. A sleeper deal so I kinda wanted to keep iron heads.
 
I have thought about that

I thought about what RustyRatRod said and going with aluminum heads and it's not a numbers matching deal. My plan was to pull my 273 Commando then make the 340 look just like it with the valve covers and air cleaner. A sleeper deal so I kinda wanted to keep iron heads.

Just paint the aluminum heads. No one will know a thing. Add up all the dough you're talkin about spending on old iron heads. That's a lot of money man and you still have old castings. Just food for thought.
 
Just paint the aluminum heads. No one will know a thing. Add up all the dough you're talkin about spending on old iron heads. That's a lot of money man and you still have old castings. Just food for thought.
Point taken. Guess it might be time for Edelbrocks
 
Point taken. Guess it might be time for Edelbrocks

Just imagine this Windsor with all the accessories bolted on it. You'll never know the difference!

PAINTED HEADS.jpg
 
I've heard of guys sandblasting the machined ends of aluminum heads to make them appear "as cast". Then paint them up and nobody will know the difference.
 
I've heard of guys sandblasting the machined ends of aluminum heads to make them appear "as cast". Then paint them up and nobody will know the difference.
Yeaaaaa, not so much as seen below.
097B12E4-4F9F-4E08-BC38-9CFA4E8A8C6C.jpeg
 
Point taken. Guess it might be time for Edelbrocks
Pretty sure you'll have more money in the edelbrocks than the x heads by a bit by the time they're are ready to run.
Get quotes before you do anything.
X heads flow decent and at 2.02 from the factory make porting time minimal to hit a good target flow of say 250 cfm.
If the spread is 500.00+ and you still haven't figured in checking/correcting the eddys...
You're leaving the '68 340 bottom end stock bore as well?
 
Just paint the aluminum heads. No one will know a thing. Add up all the dough you're talkin about spending on old iron heads. That's a lot of money man and you still have old castings. Just food for thought.

agree.. most never even noticed my alumn heads..

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DSC02551.JPG
 
Pretty sure you'll have more money in the edelbrocks than the x heads by a bit by the time they're are ready to run.
Get quotes before you do anything.
X heads flow decent and at 2.02 from the factory make porting time minimal to hit a good target flow of say 250 cfm.
If the spread is 500.00+ and you still haven't figured in checking/correcting the eddys...
You're leaving the '68 340 bottom end stock bore as well?
It needs to be bored but I'm using "stock" replacement forged pistons
 
What is your performance target, gears and tire size?
How are you going to use / drive your car?
 
I recently picked up a 340 out of a 68 Dart and tore the engine down. The block, crank, rods and heads check out fine and need very little machining. The bottom end I'm leaving it stock with the exception of a Lunati cam #10200703 (.494/.513- adv duration 268/276) but I'm torn on the heads. I don't know whether to just redo the heads with stainless valves, bronze guides and a 3 angle or do what I just mentioned with some bowl work and intake matching. I have a set of Milodon megaflow valves which came with the engine but I'm gonna have to ship the heads to get them ported. No one in NC will touch them. So to port or not to port? Is it worth it between all the shipping and what I'll gain hp wise?
If you are not concerned about #'s matching, sell the X heads, buy a set of 915 castings from Indy for $500. They come with the big valves and are ready to bolt on. Disassemble them. Do a little pocket port work on them your self ( it aint rocket science ). You are basically blending the bottom cut in to the port and correcting any minor core shift. Depending on the sale of the X heads, you might come close to having a fresh set of heads for free. I have done this - on this.

chassis6.jpg
 
You'll be fine with X heads. You might be happier with a smaller cam on the street unless you have
a high stall converter.
 
As stated the eddy heads don’t look stock to anyone but a novice. Would people notice? Probably. That being said there can be alternator fittment issues and hipo exhaust manifold fit issues with the eddy heads. Nothing that can’t be overcome easily, but keep them in mind. Unless you want the #’s matching thing or you are required to run that head, sell them and go aluminum. I have run 11.83 with my x heads but that is a pretty all out effort and why put that in a 50 year old casting?
 
If you end up keeping your X heads, talk to Hensley Racing in Knoxville, TN about porting them for you. They did a set of J heads for me years ago, and they did a good job. I was happy with the way they performed.
 
Definitely not stock appearance.lol
Exactly! Only the novice or know nothing miss the Edelbrock heads. While there ever so slightly hid with red paint, anybody into cars can see they are an aftermarket head.

To the OP, the Alternator has a slight clearance issue that can be overcome with some thinking with the Edelbrock head.

IMO, for a street driven car for a little fun, bowl ported X heads will be fine.
 
If you are not concerned about #'s matching, sell the X heads, buy a set of 915 castings from Indy for $500. They come with the big valves and are ready to bolt on. Disassemble them. Do a little pocket port work on them your self ( it aint rocket science ). You are basically blending the bottom cut in to the port and correcting any minor core shift. Depending on the sale of the X heads, you might come close to having a fresh set of heads for free. I have done this - on this.

View attachment 1715260974
Love that car.
 
I like the Edelbrocks, and locally here, it cost only $110 to have the seats touched up (for valve centering) and a quick Serdi cut below the seats.

But you are not just going to slap them on your short block and go without examining the compression ratio changes. Your real static compression ratio with L2316F stock replacement forged pistons (which I assume is what you are planning) and .039" thick head gaskets is going to be around 9.6 with the stock heads. If you put on the Edelbrocks with the 'open' chambers, then your static CR is going to jump up to around 10.4 with .039" thick head gaskets and 10.1 with .050" thick head gaskets. That is getting into 'CAUTION' territory for open chamber heads and that size of cam, but at least the AL heads will help.

With the Lunati '703 cam, DCR with the 65 cc 'open' Edelbrocks (PN 60179) and the thicker head gasket, the dynamic CR (DCR) will be 8.2 with the cam installed at the factory ground 106 ICL. Your elevation in Clayton is low so you will get the full DCR number, and that will mean you need to run pump premium and will have to be careful in tuning carb and ignition advance to stay away from detonation. Don't just slap this thing together and not carefully check ignition timing all that; and an running an AFR gauge would be wise for that DCR, IMHO. I surely would not go with any smaller cam as that would push DCR up even more. On the good side, that combination will be very torquey on the street, ought to work with the stock TC, and still breath well up at higher RPM's.

I personally would not go with those pistons you have selected, but use ICON FHR IC9975 forged flat tops and then use the closed chamber Edelbrocks (PN 60779). With shave of .010" on the block to get those pistons to zero-deck and the block trued up, and a .039" thick head gasket, you can get the quench effect going and that will further help fight detonation. The SCR will be 9.8 and the DCR will be 8.0; the whole combination is going to be less prone to any detonation. (I fact I expect it would take being pretty sloppy to do so.) The only downside of the ICON's is that you need to work on the engine balance, which involves some more $$. So all of this does involve probably $500-$700 more overall, but then engine is pretty 'friendly' to being a bit off in tuning.

Regardless, with any of these combinations above, IMHO you need to become familiar with tuning and ignition timing and cam timing topics, if you are not already there.
 
If you are not concerned about #'s matching, sell the X heads, buy a set of 915 castings from Indy for $500. They come with the big valves and are ready to bolt on. Disassemble them. Do a little pocket port work on them your self ( it aint rocket science ). You are basically blending the bottom cut in to the port and correcting any minor core shift. Depending on the sale of the X heads, you might come close to having a fresh set of heads for free. I have done this - on this.

View attachment 1715260974
Those heads need more than a pocket port.
Indy's aero head 2.02 valve heads have about no throat cut done and flow around 203 cfm out of the aerohead box...in lamens... they flow less than an x head. You could take them to another shop and improve the flow just by means of a better valave job. They dont do the 90 cut or 70, they do a 60,45,30 and that's it.

For what the op is doing, he should stick with the x heads, he can easily make about 390-400 hp with a cam in his usage range.
I made 392hp with stock xheads and a 284 .528 purple cam, ld340,headers and stock replace kb pistons @9.5 comp
 
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