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Boss vs gen 1 heads Porting question

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Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
My Gen 1 heads have the intake ports looking great with big increase in cfm and velocity over my old Boss heads.. Now the shop is finally working on the exhaust ports... Does any one know if the Gen1 head has the same amount of meat (metal) that the Boss heads have?. My guy was worried if the gen1 head can be made to have the same larger exhaust ports that the Boss has. I would imagine that they are very similer just with better alloys and CNC for the Boss heads.
 

ArizonaBOSS

Because racecar.
Moderator
8,730
2,734
Arizona, USA
I'm not 100% sure but I'm fairly confident that the Boss heads are "just" Gen1 heads with CNC porting. So assuming that is true, yes you should be good. One other thing to watch out for here is the top side of the heads--you will also have to machine some of the top side walls away to clear the larger BOSS cam lobes. There is some info out there already, you can find it probably by looking for threads about putting BOSS cams into factory Gen1 GT heads.
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
Thanks! Nice save over the exhaust cams!! Forgot that the Boss cams have 13mm vs 11mm of the GT. The heads are due for the machine shop to be cleaned up so we can do that then.
😅 😅 😅
 

Grant 302

basic and well known psychic
You guys are taxing my memory, but I thought 13mm lift cams didn’t fit in early heads without machining. I think the spring pockets needed to be cut to prevent coil bind.
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
You guys are taxing my memory, but I thought 13mm lift cams didn’t fit in early heads without machining. I think the spring pockets needed to be cut to prevent coil bind.


I found this on the Ford site... "Will work with Mustang GT 5.0L 4V Ti-VCT cylinder head with modification for rocker arm clearance". Also saw in some chats that that applies to 2011/2012 heads not the 2013/2014 heads... But cannot confirm.

Did find this though...
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
441
Southeast
Sounds right, back in 2010 the new 2011 GT 5.0l was a big deal for FoMoCo & advertised as the 5.0l was back for 2011. The goal for that engine, ‘F’ Code was more than 400 HP. F Code engines began life at 412 HP. Also under development in 2010 was The Boss 302 5.0l ‘U’ Code engine. The U Code had Ford Racing’s full attention at that time, & to make 444 HP they did it with improved Flow & a higher RPM Redline. So cylinder head porting & cams were the first of several changes in the U Code v. the F Code 5.0l.

IIRC the above discussion on valve spring clearance & seat depth, the U Code engine also has different valve springs to handle the higher RPM capabilities of the U Code engine.
 

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