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#1
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7C3 heads
I was looking thru some heads last week and came across some 7C3 heads from what I can figure out a 1973 400. Has anyone heard of these and any history, back story. Thanks in advance.
Jim
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Jim Moshier 1971 Grand Prix 462ci SD Performance 6x heads 1962 Catalina 389 1968 Firebird 400-455 I haven't decided "If we ever forget that we're one nation under GOD, then we will be a nation gone under." - Ronald Reagan |
#2
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They where a strange Head as where many from late 72 - 73 other then the 455SD head.
Fior some dam reason Pontiac reverted back Exh port wise to there first V8 heads in the mid 50's where the center Exh port divider from the head bolt on out to the flange is missing/ not cast into the Head, which sucks for Exh flow! In short they make for them being a grocery getter Head, or a good door stop or paper weight! Last edited by steve25; 10-14-2019 at 09:39 AM. |
#3
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Definitely very early 1972 heads for 400 4bbl applications. They were superseded by 7K3 early in the model year.
Do you happen to know the date codes on them? |
#4
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Thanks guys, yes very weird looking with no divider on the middle ports and would agree it would hurt exhaust flow as would the 3 tube header design.
Rocky no, I don’t have the date from the heads sorry.
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Jim Moshier 1971 Grand Prix 462ci SD Performance 6x heads 1962 Catalina 389 1968 Firebird 400-455 I haven't decided "If we ever forget that we're one nation under GOD, then we will be a nation gone under." - Ronald Reagan |
#5
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Best use would be for trade in cores....
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
#6
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I don't own these heads, as I just saw them for sale and they are asking $500 for the pair I think, The ad says a rare find....... I just thought I would inquire as I have never seen these heads before.
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Jim Moshier 1971 Grand Prix 462ci SD Performance 6x heads 1962 Catalina 389 1968 Firebird 400-455 I haven't decided "If we ever forget that we're one nation under GOD, then we will be a nation gone under." - Ronald Reagan |
#7
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Thanks, Jim.
I'm not sure they're worth $500, but they're definitely more usable than cores. They're essentially 7K3's. |
#8
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I wonder how the old timey exhaust port was allowed to be used in the early 70's?
I wonder if someone in charge at PMD got nagged to death by some old geezer engineer on the staff, about how well those old heads performed, exhaust wise...and let that design to be used on the 7C3's???
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
#9
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In the mid 50s the engineer's did not really know better in terms of Exh flow , in the early 70s I think the corporate bean counters just wanted to save on the cost of cast iron until the engineers steeped back in and said screw you where loosing performance and possibly sales!
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#10
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Well I unearthed my notes on the 72 head castings and I have this info to relay.
The early 1972 heads which by date code would have started to be cast in mid to late August of 71 and had Head codes of 7A1 thru 7E5 and they all where open center Exh configuration. The 7E5 casting was the standard 455 casting and if I recall right was a pressed in rocker stud version. The late 72 castings of 7H1 thru 7M5 reverted back to the normal seperation of the center Exh ports. Unfortunately I have no notes as to what month in 72 that factory started casting heads the right way if you will!
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#11
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thanks Steve.
__________________
Jim Moshier 1971 Grand Prix 462ci SD Performance 6x heads 1962 Catalina 389 1968 Firebird 400-455 I haven't decided "If we ever forget that we're one nation under GOD, then we will be a nation gone under." - Ronald Reagan |
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