487X head
Thread Starter
5th Gear
Joined: Jan 2017
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487X head
I have a set of 487x Cast Iron heads. I pulled them off of the 350 Block cast # on block is 3956618.
I am trying to find some information on the heads.
They have 2.01 1.60 Valves I know that much.
I have been told they are rare heads before I cut them for bigger valves and put them on my 383 I would like to know the information on them.
Anything and all will help
I appreciate it in advance.
I am trying to find some information on the heads.
They have 2.01 1.60 Valves I know that much.
I have been told they are rare heads before I cut them for bigger valves and put them on my 383 I would like to know the information on them.
Anything and all will help
I appreciate it in advance.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I've had completely done up with larger valve spring pockets, screw in studs, and 2.055 intake valves. Totally ported and they just can't compete with even a dart 200cc iron eagle head. Modern fast burn chamber technology
Thread Starter
5th Gear
Joined: Jan 2017
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Im not trying to make big hp Im building a street car with some nitrous. Im not worried about dart heads etc. I have already had them flow checked and I know what we can get them to flow with my dad being a machinist. But Im trying to find out the info before I cut them up. I have had several people saying that they are LT1 Corvette heads but I haven't figured out if they are or not.
Im building a smaller grudge/street car not trying to be fancy and let everyone know its built etc
Im building a smaller grudge/street car not trying to be fancy and let everyone know its built etc
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
They are 71 and 72 76cc chamber for the lower power level smog motors. It is possible that they were on those years of vettes. But they were in every chevrolet model as optional motors
Drifting
Joined: Jun 2012
Posts: 1,990
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From: Port St. Lucie Fl
Im not trying to make big hp Im building a street car with some nitrous. Im not worried about dart heads etc. I have already had them flow checked and I know what we can get them to flow with my dad being a machinist. But Im trying to find out the info before I cut them up. I have had several people saying that they are LT1 Corvette heads but I haven't figured out if they are or not.
Im building a smaller grudge/street car not trying to be fancy and let everyone know its built etc
Im building a smaller grudge/street car not trying to be fancy and let everyone know its built etc
if you're not building it for HP why nitrous?
Thread Starter
5th Gear
Joined: Jan 2017
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Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
W/gull sell them even with big valves
the days of old ron.slppe are OVER
go get yourslef some TFS doube lhumps or 180 ars and leave em scrathging thier head tirst me. Those old iron head sell them on ebay or toss them out even with big valves.
the days of old ron.slppe are OVER
go get yourslef some TFS doube lhumps or 180 ars and leave em scrathging thier head tirst me. Those old iron head sell them on ebay or toss them out even with big valves.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
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I have those heads on my 72 lt1 motor. They have 76 cc chambers. Nothing special. Port them since you have them
Le Mans Master
Joined: Oct 2010
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
You won't hurt anything by porting them since you seem married to them. But I agree you will get further with less work with an aftermarket head.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
3956618....302.....69....4...Z-28 Camaro
3956618....327...68-69...2
3956618....350.....69....2 or 4
Drifting
Joined: Jul 2013
Posts: 1,299
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From: Tri-Cities TN
Ditto. What you will spend in R&R the valve guides, replacing seats, cutting seats, surfacing the head, converting to studs and guide plates you would be money ahead to find somebody that will pay you big money for the heads and get you a set of aftermarket heads.
Racer
Joined: Nov 2000
Posts: 369
Likes: 1
From: Finland
The base engine my -72 had 487X heads. AFAIK they were used on both base and LT-1 engines. Supposedly they have slightly larger ports than 487 heads.
I have one old book, "John Lingenfelter on Modifying Small-block Chevy Engines", that was written before aftermarket heads had become so widely used as they are now. it listed these heads as one of the few smog heads that were worth using on a performance build.
I have one old book, "John Lingenfelter on Modifying Small-block Chevy Engines", that was written before aftermarket heads had become so widely used as they are now. it listed these heads as one of the few smog heads that were worth using on a performance build.
Last edited by Tomi72; Jan 9, 2017 at 02:55 PM.
Instructor
Joined: Nov 2012
Posts: 179
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From: West Lower Mich.
Yes the 487X heads came on the 71-72 LT-1 corvette with 76cc chamber's to lower the compression in those years. But they came stock with 2.02 int & 1.60 exh valves and with the push rod guide plates. They are good heads other than they have the larger 76cc chamber.