# 7k3 heads



## SDGoat619 (Mar 21, 2011)

I am about to pull the triger on some 7k3 heads 2.11/1.77 96cc. These heads are off a 400. The seller seems to think that putting them on a 455 should get the compression up quite a bit. I could see the reasoning behind this as I have 114cc 4x-1h heads now. Does this sound right for around 200 bucks. 

Thanks as always. 

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## 68raGTOp (Sep 4, 2011)

$200.00 sounds fair for a set of 7K3's. The 7K3 heads are approx. 96cc chambers don't know what compression ratio that will give a 455 without doing some math. But the 7K3's only have 4 exhaust bolts on each side (the end bolts are not there). So getting a set of headers to seal will require either welding and tapping two bolt bosses on each head or buying a set of brackets from a place, If memory serves me I believe called Spott's. Which is the way I went on my 7K3's. I believe these are very good heads just thought you should know about the bolt hole thing, I found out after I bought mine.


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## SDGoat619 (Mar 21, 2011)

Thanks for that great info it saved me from a giant pain in the a$$. Needless to say I ended up not going the route of the 7K3 heads. I think that for now i have settled for the 6x-4's as they seem to be a favorite for 455 builds. Any thoughts on if its worth it to convert the exhaust valve from 1.66-1.77. 

thanks as always


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## 68raGTOp (Sep 4, 2011)

Depends on how much you want to spend on the heads. In my opinion bigger exhaust valves are never a bad idea! I run a 400 myself, but I always thought the 455's liked the bigger combustion chambers? Like the 6X-8's, just my thought or question.


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