390 head identification
Printed From: TheAMCForum.com
Category: The Garage
Forum Name: AMC V8 Engine Repair and Modifications
Forum Description: AMC-made V8 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=114109
Printed Date: Apr/23/2024 at 6:30pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: 390 head identification
Posted By: mackb67
Subject: 390 head identification
Date Posted: Jan/23/2022 at 8:33pm
| Is there a way to tell if the heads on my 1968 AMX are square port or dogleg port without removing the partially rusted out headers that are on it currently?? |
Replies:
Posted By: tufcj
Date Posted: Jan/23/2022 at 8:36pm
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You could remove the valve cover and get the casting number. Bob tufcj ------------- 69 AMX 74 Javelin AMX 67 Rogue If you need a tool and don't buy it... you'll eventually pay for it... and not have it. Henry Ford |
Posted By: Heavy 488
Date Posted: Jan/23/2022 at 8:43pm
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Probably square unless someone swapped. I believe casting under the cover should be 858.
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Posted By: AMXFSTBK390
Date Posted: Jan/23/2022 at 9:01pm
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The casting number on a 1968 AMC 390 head is 318 8558 rectangular exhaust ports. ------------- Questions are powerful tools...what's in your toolbox? |
Posted By: Heavy 488
Date Posted: Jan/23/2022 at 9:26pm
I knew it had 8's and 5's in there |
Posted By: White70JavelinSST
Date Posted: Jan/24/2022 at 9:15pm
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I thought the difference between the two was readily visible with a mere look see at them. Nothing needs to come apart. The square ports don't have the dogleg
that appears in the bottom lower right of the port as shown in this photo. The square ports won't have that bump out in the headers or cast iron manifolds.  ------------- 70 Javelin SST, second owner, purchased 1972 |
Posted By: BassBoat
Date Posted: Jan/25/2022 at 3:24pm
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I have put dog leg headers on square port heads, so easiest is to pull valve cover and look for that 318 8558 number... |