66' 273 heads question

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djpearce

djpearce

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In 1966, were the heads on a 273 / 2 barrel, different than the ones that came on a 273 / 4 barrel 273 or a Commando 273 ?
 
No. All 273 heads had the same closed chamber design similar to the later 302 castings. Only difference in any 273 heads is the intake bolt angle change between 66 and 67.
 
RedFish said:
No. All 273 heads had the same closed chamber design similar to the later 302 castings. Only difference in any 273 heads is the intake bolt angle change between 66 and 67.
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Isn't that 65/66? I thought 65 was the last year for the wierd bolt angle and the 5/16 intake bolt size.
 
65Vart said:
Isn't that 65/66? I thought 65 was the last year for the wierd bolt angle and the 5/16 intake bolt size.
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I was thinking the bolt angle changed same year the left exhaust manifold changed a little. I've been wrong before.
 
thanks guys ... I didn't think there was a difference but was unsure. The intake bolt changed between 65-66 as far as I've been told.
 
I found out the hard way shopping for an intake. I found a correct for the year Eddy D4B on Ebay so I didn't have to buy a new intake and hog out the bolt holes (destroy it). I have not installed it yet. Car runs good and I have not decided what I am planning for this motor.
Anybody run a D4B? (sorry to Hijack your thread Dj)
 
RedFish said:
No. All 273 heads had the same closed chamber design similar to the later 302 castings. Only difference in any 273 heads is the intake bolt angle change between 66 and 67.
Click to expand...

66 and 67 should be the 920 casting which is the better head.
 
dart4forte said:
66 and 67 should be the 902 casting which is the better head.
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Those are 920's I have a 234 and a 920 on my 273. Both are 66 heads but the 920 was also a 1967 head. Mike
 
RedFish said:
No. All 273 heads had the same closed chamber design similar to the later 302 castings. Only difference in any 273 heads is the intake bolt angle change between 66 and 67.
Click to expand...
The '64-5 models generally used the 315 casting....the '66-7 models, the 920 casting, and the '68-9 models, the 275 casting. The 315's and 920's, with good high octane fuel, perform well on a 273. Their drawback is crack problems and pump gas ping problems. The 275 casting is open chambered and doesn't have any particular crack problems so it's better suited for a pump gas daily driver. Use the '72-4 version and you get hard seats too! The 273 and LA318 used the same castings in the same year but there were some crossover stuff that is the exception to the rule. I've had 315 castings machined from the factory for the '66 intake and 920 castings with the '65 machining! Maybe different plants got the new castings at different times and just kept using them until they ran out? Very weird....
Thanks, Mark
 
Rcuda2 said:
I think 273 4 barrel heads have slightly stronger springs.
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Correct but who in their right mind is going to resuse 40+year old valve springs? Get a new set to match the new cam!
Mark
 
djpearce said:
thanks guys ... I didn't think there was a difference but was unsure. The intake bolt changed between 65-66 as far as I've been told.
Click to expand...
That's correct for the most part....along with a different intake gasket.
Thanks, Mark
 
It's slightly different around the water port area...where the side gaskets meet the end gaskets (sponges?) I've used RTV and made them work but if you're not carefull, they'll leak.....sometimes water into the lifter cavity which can be a real mess. I think Felpro still makes them but I haven't bought the early set in years so am not positive. I used to have an NOS Mopar set around here somewhere.... if I find it, I'll post a photo of the difference.
Thanks, Mark
 
i ran a D4B on my 64 Barracuda wayyyyy back in 1970- 1973. It ran like a raped ape. I'm building another 273 now for a '65 /6 Barracuda and finally found another D4B for it. As soon as I fix all the little heli-coil problems I'll be ready to install it and hope to swap out the engines shortly after that.
 
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