Head Swap

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MoparDaddy

MoparDaddy

Damn Right I Carry!
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Is there going to be a negative power difference if I go from a 1973 cyl head to a 1977 super six cyl head with 1bbl intake?
 
Wow some thing i dont know ... well i will be looking in on this post thanks chuck always wanting to learn
 
As Paul noted, the only appreciable difference will be going from a head with drool tube to one without. Other than that, all the heads are pretty much the same.....unless you get into the truck stuff. Then there's a difference in the valve cover, but that's about it I believe. If I am wrong, I fully expect Slantsixdan to come put the smack down on me, as well he should. lol
 
Awesome! That was something else I meant to ask. If the truck head was better, but that's been answered.
 
Now with this being said. How is that the 60-71 slants had about 125hp the 72-74 had 105ish so on If the heads are essentially the same?
 
the difference in horsepower was because they were rated net horsepower, not gross. what that means is before they rated all engines without things like the alternator and aircleaner. the feds change the rules and made all manufactures to use "real world" numbers. if you look at all engines you will see a similar drop in horsepower.
 
I figured it was something along those lines, but I figured I would ask to be on the safe side
 
There ARE HP castings to be had for the slant, but none were made here. If you're lucky enough to find an Argentine head, they had big vaves and closed chambers. But they're like hen's teeth.
 
64Lucy said:
Weren't the Aussie's "Hemi" heads like that too?
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No. The Aussie Hemi 6 is a completely different engine altogether. It is a conventional straight 6, not a slant.
 
Great Thread Chuck really helps to learn something new here.
 
A lot will depend on whether either casting has been milled in the past. If they're both stock virgin castings, there probably isn't much difference in the compustion chamber size but, I admit, I haven't CC'd the two castings in question to see what the difference is. You can mill the head down a bit if you want to increase the compression ratio.
 
The later cams were a tad bigger to compensate for some smog crap. I know EGR equipped motors had a bump in the heads (V8's) for some reason, but I think most L6 heads were about the same, maybe hardened exhaust in the later years.
 
Nice to know. I want to put a little bit bigger cam in it anyway just to add more pep to its step
 
Chuck take a look through the /6 threads here and you should be able to find more information on where to pick up a cam.
 
Comp cams has one for about 300 or so with lifters that my dad and I were looking at, but I'll do that! New thread, here I come!

Hey! It just hit me. Slantsixdan hasn't chimed in on this at all. That's wierd
 
64Lucy said:
Comp cams has one for about 300 or so with lifters that my dad and I were looking at, but I'll do that! New thread, here I come!

Hey! It just hit me. Slantsixdan hasn't chimed in on this at all. That's wierd
Click to expand...

Actually Chuck if you read through the different threads you might find what you need. If you want to come over,give me a call.
 
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