Yah, the 93-97 GT40 heads burn much cleaner due to the chamber size. For the 97 on wards, it was spark plug positions and the chamber size changed again (GT40P).
Two pages to read below, and s video.
There were 1500 factory aluminum heads on Australian XR8 5.0's with the 295 hp engine for 12 months, then they reverted back to good old iron GT4OP's on the 335 hp 342 stroker. They were CNC machined by Yella Terra Australia for extra performance.
Never forget, the 1991 European Pantera 2 which was downgraded to an extensively modified 5 liter Mustang engine that year...it generally made 305 hp with your heads. The next year, it was downgraded to the 248 hp US emissiobs version. Each generally had more power than most of the US emissions 351C used in US Panteras till 1989. (248 in the Pantera L, to as much as 300 hp depending on the year and State emissions requirements).
See the only 300 hp AmeriSport 87 GTS-5.
The Pantera 2 made 5 hp more than the US emissions engines
https://youtu.be/j3OJGBbfWmc
The iron head GT40 and GT40P info
http://vb.foureyedpride.com/showthre...nd-GT40p-heads
The change happened with the 1993 and then the OBDII versions. Generally, its okay to fake hook up the lines since there is no malfunction light on carb 85s.
The purge and evap and TAD/TAB solenoids can stay, so can the EGR. The Carb 83 to 85 4V's are a twin stack of 52 cards each. One change can impinge on 104 other parts because the 83 to 85s had many state and model year changes. The AIR system should be an easy delete compared to the other stuff.
Connect With Us