New GT40P Heads Mustang 302 351

A

asian tony

New Member

Oct 27, 2005

12

0

0

Jul 6, 2006

#1

• Jul 6, 2006

• #1

hey guys,

i've got a line on some New GT40P Heads for a Mustang 302 351. will they fit on my stock 1966 289? performance gains? header clearance issues? apparently the plug holes have been moved a little bit on these heads. they are brand new, and the guy is asking $200 for them. heads only though...

tony

 

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D

D.Hearne

New Member

Sep 29, 2000

11,730

6

0

south louisiana

Jul 6, 2006

#2

• Jul 6, 2006

• #2

The "P" chambers are a full 10cc's larger than your 289 heads. Expect a drop in compression of at least a full point. The gain you see will be partially negated by the compression drop. Header choices will also be limited due to the plug angles. You may also have issues with the coolant ports in the deck face.

 

Dark Knight

Founding Member

Feb 1, 2000

2,578

0

0

Chandler, Az.

Jul 6, 2006

#3

• Jul 6, 2006

• #3

Also, if they're bare, expect to put some $$$ into valves, springs, retainers etc. Might want to convert them to screw in studs too before you put them on.. if you get them..

 

F

ForceFed70

That's why they call it "dope"

Founding Member

Dec 6, 1999

4,818

1

69

BC Canada

Jul 6, 2006

#4

• Jul 6, 2006

• #4

Would be a good set of heads if you are planning a power adder at some point.

Otherwise you'll want to swap pistons or have the heads milled. Which usually means it's more economical to buy a different set of heads unless your getting them for really cheap.