NAPA auto parts/ 302 cylinder heads

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Louie70Dart

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I was looking for heads the other day and ran across this at NAPA. Worth taking a chance?
Maybe more info will help. It's a stock 318 that I plan on going with shorty headers on it with dual 2 1/2 in all way back. I have electronic ignition on it now. I'm not sure if the heads have the hardened exhaust seats. Stock 7 1/4 rear and tires and 904 tranny. Get a stock 340 cam and new lifters. And an intake and 650 carb also. Nothing wild, just a little more power until I get the 340 I have going. Thanks.

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=MCYCHR4033_0243714669
 
I'd spend the money EQ's, myself. Modern casting, all new bits, great flow, etc. etc.
 
Well, I want to keep it sorta low cost. I already have a 340 that needs rebuilt. I also have some X-heads that have been pocket ported to go on that. I just don't want to spend time and money on the 340 yet.
 
Louie70Dart said:
I was looking for heads the other day and ran across this at NAPA. Worth taking a chance?
I'm not sure if the heads have the hardened exhaust seats.
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I'd be willing to bet they DON'T have the hardened seats. Dang, they aren't exactly cheap, are they? I've got a '91 Dodge Ram with a rebuilt 318 that seems to have a problem with coolant disappearing, and the exhaust smells like coolant. I think one of the heads may have a crack. I wanted to find some 302's for it, and those look all right......but for that kinda money, I'd want hardened exhaust seats.
 
You might want to keep watch for a set of 302's on the secondary market. Commonly avail for $100-200/pair if you stay paitient & diligent.
 
bad440 said:
dont 302 heads come with hardened seats already?
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Y'know, that's what I always thought. Then my machine shop guy told me that they were not (I had a set of 302's rebuilt before). I couldn't believe it! I thought all heads from the 70's on up had hardened seats.......turns out the seats had a hardening applied to them. I got a strong magnifying glass and looked closely. My machinist was right. There was no hardened seat insert pressed in at all. It was all cast iron.

So....once the seats get a valve job, NO hardening anymore, right?! What a crack-up.
 
I called Moore Cylinder Head and asked if their heads came with hardened seats. I was told yes. Next was what are these for? I made the mistake of telling him what I planned. He said that they would not sell them because I was going to use them as a performance item. What? I think the big thing was about core return, but I might be wrong.
 
If you buy through NAPA don;t worry about Moore's warranty. But - They will be similar price as the EQ heads because you don;t have cores for them... So I'd just get the EQs.
 
The seats were induction hardened high nickle castings. Not the same as a hardened seat installed.
 
RedFish said:
The seats were induction hardened high nickle castings. Not the same as a hardened seat installed.
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This ^ x2

They are ductile hardened. All of them are. They did not recieve ductile hardened seats that the heads were simply cut for and pressed in. Both methods work for gaining seat strength for unleaded fuel. Not all machinists are aware of both methods. One looks like nothing at all is done, until you start playing with them and examine how the exhaust seats usually don't have any pitting.

I have a set and they are a fantastic upgrade on any 318. They will up the compression on your engine and Napa won't sell you a set of cracked heads. They check them for cracks before machining them.

If you do buy them, you may have a little grinding to do on the back of the driver's side head, so an older, factory 318 exhaust manifold will clear them. It's not much, if any. You also have to use 1/4 20 set screws and tap, to tap and plug the exhaust air ports, just under the exhaust ports to use them without an air pump. It's really minimal clearance and plug work, well worth the effort.

If you use that 340 cam, be sure that the heads do not have the thicker, rotater retainers on the exhaust valves, with short springs, or you may see problems with guide clearance. Easy fix with no rotater retainers.

Here is a link to some valve retainer to guide numbers I posted a couple days ago about doing just what you're talking about. -

http://www.forabodiesonly.com/mopar/showthread.php?t=229924

I replaced my valves and springs with standard 2/4 groove int./exh., but the install height is the same on the valves. I did it to get rid of the rotaters that my 302 heads had.
 
Louie70Dart said:
I called Moore Cylinder Head and asked if their heads came with hardened seats. I was told yes. Next was what are these for?
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Lead that was used as a cheap octane level booster (longer, hotter burn) helped condition the seats on the cylinder heads, where the hot exhaust passed by them through the valve. After California's EPA found lead sediment settling from the sky in high traffic areas, they quickly changed to unleaded fuel. Running unleaded fuel in an engine with non hardened seats will eventually burn/ char the seats from heat and you will have a bad exhaust leak and possibly a cylinder head that is useless, depending on how bad the burn is.

Louie70Dart said:
I made the mistake of telling him what I planned. He said that they would not sell them because I was going to use them as a performance item. What? I think the big thing was about core return, but I might be wrong.
Click to expand...

They likely want a set of 302 heads in return, opposed to the open chamber, non swirl port heads you have. It has nothing to do with your idea and entirely to do with paperwork and the cores you can't return on a technicality.

I like when I take tires and wheels to Discount and the guy asks what vehicle they're going on... Like I'd let them anywhere near my car with their impacts set to kill. I usually tell them that they're going on a 1938 Morgan. Most of them don't know to ask why I have 4 or 5 of each and not 3.
 
cudavert said:
Y'know, that's what I always thought. Then my machine shop guy told me that they were not (I had a set of 302's rebuilt before). I couldn't believe it! I thought all heads from the 70's on up had hardened seats.......turns out the seats had a hardening applied to them. I got a strong magnifying glass and looked closely. My machinist was right. There was no hardened seat insert pressed in at all. It was all cast iron.

So....once the seats get a valve job, NO hardening anymore, right?! What a crack-up.
Click to expand...
gotcha,kinda like the nitrided crank deal....:tard:
 
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