New GT40P Heads Mustang 302 351

[asian tony]

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

 

[D.Hearne]

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]

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..

 

[ForceFed70]

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.