Heads
Cargo Master
Joined: Mar 2010
Posts: 3,342
Likes: 294
From: Laramie, WY
Gt40p outflows the Gt40 by about 5% despite smaller exhaust valves, and the chamber design is more efficient. But, that better chamber comes at the cost of the awkward plug angle. Most LT headers can work despite that. However, for a no bs install the Gt40 will be easiest.
The combustion chamber is a little tighter in the Gt40p as well.
The combustion chamber is a little tighter in the Gt40p as well.
Cargo Master
Joined: Mar 2010
Posts: 3,342
Likes: 294
From: Laramie, WY
They can help. I only needed 1 90degree boot, on #7. The rest had plenty of clearance. A short plug could be used too. Different headers might not need that stuff at all. Where people run into real trouble is trying use shorty headers that hug the engine, like in a Mustang.
Cargo Master
Joined: Mar 2010
Posts: 3,342
Likes: 294
From: Laramie, WY
Seven of them are easy, but cylinder #7 is difficult. I had to modify a socket. I've heard Flotech headers fit well in that regard. I have some Chinese ss headers, they needed a lot of massaging to fit: tight to #7, hit the starter, and the flange holes were way off.
Lead Driver
Joined: May 2011
Posts: 5,798
Likes: 453
As boarding said, flowtechs and most long tube headers designed for the trucks have plenty of plug clearance with p heads, as the primaries come straight out before beginning their bend down toward the collector. With shorty headers, you'll have to get creative to install and access plugs
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Mountain Pass
Joined: Apr 2017
Posts: 143
Likes: 0
When I put my gr40ps on I found that the plugs weren’t as bad as everyone made them seem. But #7 is definitely difficult but I’ve seen worse in my dads jimmy with a 4.3
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