I think I know the answer…

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Nope. There was a change around 67/68 that I remember, was always told to use 68 up head for better performance, which includes both drool tube and peanut head.
It's in the articles section at the /6 site as well as in Dutra's book.... Not much difference in any of them. I think the drool tube heads are lighter, so there's that.. clean up the porting and it matters less.
meh, I disagree the later head is better for performance. It's the same cc chamber, the same valve sizes and essentially the same port configuration. "Revised" is the term Chrysler used. I "guess" if you really get technical about flame propagation and all that nonsense, the revised head might be better, but you'd never feel the difference.
 
I'm not out for the last 0.001 of a second off of the 1/4 mile ET, my motor will probably never see the high side of 4000 rpm, so no/ I probably won't notice the difference.
 
I have a hydro head sitting loose in my shop. What measurements are you curious about?
It's more about the form & shapes as much as dimensions, which are much easier to measure if You make a mold of it.
 
I'm not out for the last 0.001 of a second off of the 1/4 mile ET, my motor will probably never see the high side of 4000 rpm, so no/ I probably won't notice the difference.
I rarely rev Vixen's engine past 4K, even though it really starts pouring it on about then. I need to to last so, I don't abuse it.
 
Member "My 68Barracuda" has done some molds of ports on these heads, I haven't seen him around here in a while.
He had an actual flow bench in his garage for a while, his was at 10" not 28" like many.
The head on my slant was actually flowed on that bench for ***** and giggles while he had it, I m not sure which one but one of our PA members now has that bench....
He showed me some of the molds he'd taken while I was out his way....
I don't remember there being much difference there in any of the the different heads, stock anyway. The thing I remember about pre 68 was there was a dime shaped protrusion in the casting that the after 68 ones don't have.... Supposedly they run better without that, and something about better emissions readings when they took that out.
And hydro vs solid lifter equipped heads I don't think that there was much if any difference in port or CC shape....
 
Back to the original post:

New seals in and new plugs without washers and no leaks at all. Cleaned up the tubes good and painted them with caliper paint to make seeing leaks easier.
IMG_2469.jpeg


Thanks again
RGAZ
 
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