Hitman's Pontiac Trans Am Forum
Trans Am Information => Restoration => Topic started by: 1981turbotransam on April 19, 2009, 07:57:57 PM
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i just got a set of heads at charlotte and i need them to be ided for me please. on the sides of the heads they say 6x4 waht are they?
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Sound like heads off a Pontiac 400. Don't know the combustion chamber size off hand but could probably look it up for you if you need it.
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i think they are the 220 hp heads not positive
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Copied this from this page here. Its a good source for Pontiac head info.
http://ronspontiacpage.com/reference-pages/stockheadspecs.htm
(http://i80.photobucket.com/albums/j195/sdragon555/heads1.jpg)
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Depending on the date code they are either off of a '76 or '77 350 or a '77, '78 or '79 W72 400. They all used the same head.
2.11"/1.66" valves and 94cc combustion chambers
(http://i20.photobucket.com/albums/b230/SirLDragon/tech/Pontheadid.jpg)
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wahts the hp rateing?
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i think on the secondary stamp there is an 8
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Then they're 6X-8 heads. Not 6X-4. Same head with 101cc chambers. Lower compression. They were the ones used on the L78 400s.
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wahts the hp rateing?
The heads don't have a HP rating. That all depends on the engine they're bolted to.
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but the casting number says 6x4
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There's a 4 in the center right next to the 6X? or is it over to the right like in the pic I posted? That large 4 you see in that pic is not part of the casting number. The last digit in either the 6X-4 or 6X-8 ID is the secondary stamp number.
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mine look like the one in the pic
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Are you sure you're reading that right? For giggles and grins, what does the secondary stamp (shown in the pic above) say? ???
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Are you sure you're reading that right? For giggles and grins, what does the secondary stamp (shown in the pic above) say? ???
i think on the secondary stamp there is an 8
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Larry, that's what I thought he said, but then he said they was a 6X4 on the center ports. I've never seen that, so I'm thinking that the casting numbers are eroded and hard to read and may be some other 3 letter/digit number. So I'm confused right now as to what he does have, and thought it worth a second look. ???
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I think he's confusing the M 4 on the right hand exhaust port as part of the ID code.
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If they are the 4's with stock 400 setup your looking to get around 200 horse power, if they are the 8's with a stock setup you will be getting around 220. What you do now is all up to you. if your lookin for performance those are great heads for a super charger, or they work nicely with a stroker kit, however you wont get too much power out of them just rebuilding the motor and putting in a more agressive cam and new intake. It thats the kind of motor you are looking for then you may wanna try and find yourself an older set of heads with a chamber size in the 72 -80 cc range. However a stroker kit only runs you about 1800 bucks and if your thinkin about rebuilding the motor you will need new pistons and rings and a crank balance prob anyways. so id go with that. Don't do what i do and not plan out your motor before you start. :) good luck. Think BIG
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If they are the 4's with stock 400 setup your looking to get around 200 horse power, if they are the 8's with a stock setup you will be getting around 220.
I think you have that reversed. The 4s are the smaller cc head and would give higher a compression ratio. Those are the ones used on the W72s.
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whoops you are correct. my mistake so yeah with a stock setup, with the 4's you will get 220 and with the 8's you will get around 200. :/
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so where do i need to look for a 4 at on the exaust ports or what?
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it will be on the center ports
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so where do i need to look for a 4 at on the exaust ports or what?
Where the picture shows the secondary stamping.
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haha i think i need to not post anymore for today i keep messing up orders of things. i have officially lost posting privlidges till midnight. im sorry.