Porting my j heads

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May 7th, 2018, 10:43 AM

6t7

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Join Date: May 2018

Posts: 1

Porting my j heads

Greetings, I have recently bought a ‘67 Cutlass with a rebuilt 455, not sure of the year, it’s got j heads. It has plenty of power as is, but more is better, right? I have done a couple of home porting jobs that have made a noticeable improvement in get up and go. Any tips \ advice on which areas to concentrate on, how much to remove would be appreciated. Thanks

May 7th, 2018, 12:12 PM

oldcutlass

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Join Date: Oct 2009

Location: Poteau, Ok

Posts: 40,521

Welcome to the site, post an intro in the Newbie section when you get a chance. Although its about sbo heads, this is a really good read.
https://classicoldsmobile.com/forums...echniques.html

June 17th, 2018, 11:59 AM

67 Cutlass Freak

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Join Date: Apr 2010

Posts: 978

Hey Eric that's not just SB heads. I showed some G's and C's being ported in that thread as well. Same techniques used for both SB and BB.

June 18th, 2018, 06:55 AM

74sprint

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Join Date: Apr 2014

Location: Winnipeg

Posts: 122

'J' Heads

Quote:

Originally Posted by 6t7

IMHO Don't waste your time with 'J' heads. Even with a street/strip port job, on the flow bench they flow no better than stock untouched 'G' heads. If you can, get at least 'G' heads, 'C' of course would be the best iron or even go with cheap aluminum ones if you can afford them. But J's are boat anchors because of their choked raised floors for additional cooling and are designed for very high swirl, way too much swirl.

Ray