Ok, I have been on this site for many years and there has been no clear cut debate on aftermarket heads and PERFORMANCE. We all know that pretty much every aftermarket head has better castings and less prone to cracking.

I am thinking that the edelbrock heads are the only heads out there that truly offer a performance upgrade over stock heads. Reason being is the extra compression bump.

But is there really enough of a flow difference from stock heads and Clearwater/Odessa, INDY RHS, and the Iron Ram heads?

My thought on that is that valve size may be the only thing that would offer a performance upgrade. And I am shaky on that idea because with my mods, I am not sure that 2.02 valves would help performance as my truck is basically stock. Although i do have custom tuning with Sean.

I guess this is a poll:
1. Edelbrock performer heads
2. Indy heads
3. Iron Ram heads
4. Odessa/Clearwater

Does anyone know performance gains from each over stock?

 

Would have to have a look at various things like Runner Volume, combustion chamber design, and valve size. A lot depends on where you want your power band to peak. If you want low-end grunt, and aren't as concerned about upper RPM range, stick with the smaller valves/runners. (better flow velocity promotes cylinder filling at low RPM) If you want more mid-upper range power, larger valves/runners are where you would want to be. (better flow rates at higher RPM) Intake manifold also plays a role here.....

In the end, it isn't just 'one piece' that improves performance, its having ALL of them geared toward the same purpose. (heads, cam, intake) Granted, the kegger is rather restrictive, and isn't 'best' at anything... sure, it has the nice long runners to promote low-end grunt, but, the runners aren't really large enough, and the kegger runs out of steam pretty early in the game. Reminds me a lot of the original Tuned Port Injection GM put on Camaros and Firebirds starting in the mid 80's. GOBS of low end torque, but, dropped off FAST after about 4000 RPM. Would have made GREAT truck motors though..... mine seldom sees 3000 RPM, let alone 4000+.

 

Let's hear some feedback on this.

What about adding Cific heads to the list?


Found an article of interest maybe: http://www.hotrod.com/techarticles/e...e/viewall.html

Another article just for reference for noobies like me:

http://www.off-roadweb.com/tech/1010...ion/index.html

Found a couple info threads here:
https://dodgeforum.com/forum/2nd-gen...ich-heads.html

https://dodgeforum.com/forum/2nd-gen...ter-heads.html

https://dodgeforum.com/forum/2nd-gen...0-rebuild.html

I can't seem to find a thread I found that talked about EQ heads...?


Main thing I've picked up on is there is no merit to reman the heads. In consideration of HeyYou's response above, larger CFM is probably the biggest aspect with respect to OPs query on performance? Assumption is other mods in place to utilize.

I'll ask a basic question though and what will drive choice between iron vs al aftermarket heads?

 

According to popular theory, aluminum heads are less prone to pre-ignition, so, you can bump compression ratio slightly, as compared to iron heads.

Aluminum heads are lighter........ not that I think that is such an overriding issue on 5000+ pound trucks......

Easier to machine?

Weight aside, a properly built engine will work just as well with either material.

 

I take it you dont buy into the whole dissimilar metals causing issues from expansion and contractions rate theory like often used for plenum plate failure?
ironically didnt Gm have issues with aluminum heads warping for some reason? I thought there was some down side to them? I know the vettes have been using them since 86.

 

It may be a contributing factor. I am not really an engineer. (I just play one on TV......)

Also, the heads are torqued to a SIGNIFICANTLY higher value than the plenum plate....... Dodge has acknowledged that the stock bolts were too long. Though I note they haven't done a recall, or Special Policy Adjustment to fix it..... Not that I expect they would....... (though it would be nice.)

 

That theory just doesn't hold up when applied to the plenum gasket. I did the math a while back and discovered that the relative motion isn't anywhere near great enough to stress a good quality gasket to the point of failure. I posted something about it here in the forum but I'm way too lazy to go dig it up.

Overheating was the reason. It holds true on these engines, too, that the center two bores run hotter than the outer two so if you manage to run it hot enough to spew steam you also run it hot enough to risk warping aluminum heads.