I have an old set of Blackjacks on mine, a couple others are running Hooker 6901s. Either way you'll probably have to use Accel "shorty" plugs on the driver's side and 90* HEI distributor cap boots on the plug end of the spark plug wires.
Any header that fits the 302 will "bolt up" but plug access is difficult, and fit in the engine bay can be an issue. There are lots of threads (5 or 6) regarding the GT40p heads and headers. I invite you to do a search on GT40P and check out my website for detailed description of the issues, and how I solved them. All of this is recent, like within the past 3 or 4 months, and there should be lots of pictures to get you a perspective of what you are getting into. Don't be discouraged. The heads flow really well, and gave me all kinds of extra horsepower. I followed bmcdaniel's guidance on much of this project, and cannot thank him enough for the help.
Hhmmmph. $13 dollar spark plugs. Double header gaskets. HEI terminal boots. Burnt wires. Oh hell yeah. Where do I sign up for these wonderful GT40P heads???
Call the guy at www.fordpowertrain.com. He makes a TRI-Y for mustangs / cougers that he says will work with GT40P heads.
Not everyone can afford or needs $1000 -$1300 aftermarket heads. If you're on a tight budget and have to use factory irons you might as well use the best flowing ones Ford made for small block Windsors. (I wouldn't mind having a nice set of aluminum heads but Santa keeps letting me down, I'm sure he will this year,too ) My strictly street driven engine combo is built for lots of low rpm torque and these heads provide that. I didn't have to double up the header gaskets and I've never burnt any wires.
I AGREE...I have GT40's...they were FREE, cam off a friends Cobra. I did a search & with a little pro porting & oversize valves will support 400hp & alot of torque. For the street, this is a plus.
Don't get the wrong idea, guys. I'm glad they work for you. Reckon I'm a bit biased in my viewpoint because I can take just about any cylinder heads and make them work pretty good. I'd rather spend the time grinding heads than fighting plugs and wires and all that. But ya'll do know there are used Dart heads out there for around $500...right????
heads were at a good price,$350.00,and was new,as far as extra cost,plugs,double gaskets ect,i'll just have the wife work ot lol