Windsor Heads - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

psixr6 · 05-12-2005, 00:48

Hey Guys,

Just like to clear up a question i have. I have heard for used "GT40" heads on later model windsors, i think AU onwards. Is this true or not???

Is it worth changing the heads on earier windsors, What are your thoughts.

Looking at getting an ED-EFII V8 Falcon. Whats should i look out for???

Allen

!Gn|T|0n · 05-12-2005, 01:43

The early windsors are very restricted. The inlet manifold is arguably the most restrictive part. If you replace that, the MAF housing and then heads you'll have improved significantly. The AUs do have GT40P heads. They are still iron and weigh in at approx 22kg each but boast a much more efficient design. Some good results (although not as good as aftermarket heads) have been found from porting the standard E7 heads. I'm running ported E7's and have noticed a decent improvement. Do a search and you've find heaps of help on windsor heads :)

EDXR8 · 05-12-2005, 06:06

Yeah AU's run GT40P's which flow almost 50% more than the stock E7 heads. Although aftermarket heads are nice, the GT40P's flow enough for 180-200rwkw and unless you stroke the engine you are not going to get that much more out of a streetable 5L anyway. The best thing is they can be found fairly cheap, anywhere from $800-$1200 which is about 1/2 that of the nearest aftermarket head.

psixr6 · 05-12-2005, 23:17

Ok cool.

Then is there much difference between the AU-AUIII models??? As in the way they were ported from factory. What did ford do to make the AUIII 220kw and the first AU i think high 190's kw.

Whould you notice the difference if u did a head swaap on an ED vintage falcon???

!Gn|T|0n · 05-12-2005, 23:23

Well as stated before, the heads are not the only restriction. Although the GT40Ps are significantly better heads than the E7TEs, they will only flow as much as the rest of the intake will - a chain is only as good as its weakest link. To be honest I'm not sure exactly what gains you'd see doing a head change only and you'll find that usually people work their way up to doing the heads preferring to change the MAF, snorkel, TB and intake first. As for your other question, I'm not sure of all the differences but I know the cams were different. Possibly differences in headers / exhaust and firmware presumably too.

EDXR8 · 05-13-2005, 00:03

The stock heads are the biggest restriction followed by the intake and then MAF, so changing heads only will give you decent gains but you won't see the full gain until the intake is changes and maybe the MAF. People normally do it in reverse because of cost.

AU1 185kw and AU2 200kw engines use standard GT40P's, the 220kw engines got Yella Terra modified heads consisting of larger and better valves, some port work in the bowl area and port matching which uped their flow by 10%. If you can get the 220kw heads then obviously they are better but finding them is difficult and they will probably cost a bit more too.

psixr6 · 05-13-2005, 17:51

IS there any ways of differentiating the different heads, stamping marks of some kind to tell the heads appart.

Allen