GT-40 Irons??

03-10-2001, 01:16 PM

I am planning the old cam, heads, and intake mods for my steed, and i was curious about the GT-40 irons. Im not looking for ultimate performance, just a decent improvement over stock heads, and emissions is a must because im in Ca. Im planning a Cobra intake, E303 cam, and GT-40 irons. My question is, is this a good combo, or should i get different heads? And if so, which?

rtz · 03-10-2001, 01:33 PM

Check this car out:
http://www.alternativeauto.com/cars/dan_sweeney.html

I'm planning on building something similar myself.

MDM · 03-10-2001, 02:22 PM

I am running them on my blower car-ported, polished, and cut for o-rings + wire-loc gaskets. I have a GT40 intake 1.6 FMS roller rockers and e-cam. The heads work well but for the weight savings and detonation protection, go with aluminums, especially with all the choices out there today. Aluminum offerings were not nearly as plentiful when I set my car up. Trick Flow makes a nice set, but you really can't go wrong with any well known manufacturer. Just make sure they are setup for emissions and you'll be set.

03-10-2001, 03:32 PM

Thanks for the replys, I was under the impression that aluminum heads would change my emissions to the point where i couldnt pass emissions tests.

chris91LX · 03-10-2001, 04:14 PM

Check out the group purchase for the AFR's on this message board posted by 2fastLX. Great heads (aluminum), emissions legal factory replacement with great performance numbers.

------------------
91 LX 5.0
Z t-5, 3:73 gear, Vortech 73mm Mass Air, Accufab 65mm TB, BBK underdrives, Crane HI-6S Ignition, BBK unequal length headers, Bassani x pipe, 2.5" Dynomax Super Turbo cat back, Kenny Brown Super Subs, Factory Five Control Arms, Mac cold air kit and more to come!

Stang_ROTY · 03-10-2001, 05:01 PM

Be careful of those AFR's if you MUST pass. I read an article in MMFF and they put a set on Ford Racing Crate 393 and it produced up to 75HP but they doubted the true "streetability" of the AFR's. That was one of my choices originally but I'm really worried about passing so I went with the Edlebrock's Performer RPM. They're cheap and they'll pass.

cojonepony · 03-11-2001, 12:23 PM

Let's not confuse the guy too much O.K. The GT-40 irons are fine for a mild set-up. A Crane 2031 with 1.7RR's should easily pass emissions with those heads. The AFR's are emissions legal in the sense that they have thermactor capability which the Performer RPM's don't. The small AFR's (165 CC) should pass with the right cam and with cat H-pipe (of course), but they're an expensive choice even in a group purchase. I just bought a set so I should know. heh,heh,heh

03-12-2001, 08:24 AM

Thanks for the suggestions, One last thing, i dont know much about roller rockers, but do you think a 1.7 set would be too much for the e303?

cojonepony · 03-12-2001, 05:10 PM

Some people use the 1.7's with the E303, but in your case you might be better off with 1.6 ratio rockers since you're concerned about emissions. The E303 is borderline as it is when it comes to passing smog tests.

03-10-2001, 01:16 PM	#1
Bangin Gears Guest Posts: n/a	GT-40 Irons?? I am planning the old cam, heads, and intake mods for my steed, and i was curious about the GT-40 irons. Im not looking for ultimate performance, just a decent improvement over stock heads, and emissions is a must because im in Ca. Im planning a Cobra intake, E303 cam, and GT-40 irons. My question is, is this a good combo, or should i get different heads? And if so, which?

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03-10-2001, 01:33 PM	#2
rtz Registered Member Join Date: Feb 2001 Location: Edmond, OK Posts: 180	Check this car out: http://www.alternativeauto.com/cars/dan_sweeney.html I'm planning on building something similar myself.

03-10-2001, 02:22 PM	#3
MDM Registered Member Join Date: Feb 2000 Location: Flemington, NJ USA Posts: 166	I am running them on my blower car-ported, polished, and cut for o-rings + wire-loc gaskets. I have a GT40 intake 1.6 FMS roller rockers and e-cam. The heads work well but for the weight savings and detonation protection, go with aluminums, especially with all the choices out there today. Aluminum offerings were not nearly as plentiful when I set my car up. Trick Flow makes a nice set, but you really can't go wrong with any well known manufacturer. Just make sure they are setup for emissions and you'll be set.

03-10-2001, 03:32 PM	#4
Bangin Gears Guest Posts: n/a	Thanks for the replys, I was under the impression that aluminum heads would change my emissions to the point where i couldnt pass emissions tests.

03-10-2001, 04:14 PM	#5
chris91LX Registered Member Join Date: Oct 1998 Location: Suburban Chicago, Hanover Park Posts: 695	Check out the group purchase for the AFR's on this message board posted by 2fastLX. Great heads (aluminum), emissions legal factory replacement with great performance numbers. ------------------ 91 LX 5.0 Z t-5, 3:73 gear, Vortech 73mm Mass Air, Accufab 65mm TB, BBK underdrives, Crane HI-6S Ignition, BBK unequal length headers, Bassani x pipe, 2.5" Dynomax Super Turbo cat back, Kenny Brown Super Subs, Factory Five Control Arms, Mac cold air kit and more to come!

03-10-2001, 05:01 PM	#6
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	Be careful of those AFR's if you MUST pass. I read an article in MMFF and they put a set on Ford Racing Crate 393 and it produced up to 75HP but they doubted the true "streetability" of the AFR's. That was one of my choices originally but I'm really worried about passing so I went with the Edlebrock's Performer RPM. They're cheap and they'll pass.

03-11-2001, 12:23 PM	#7
cojonepony Registered Member Join Date: Feb 2000 Posts: 132	Let's not confuse the guy too much O.K. The GT-40 irons are fine for a mild set-up. A Crane 2031 with 1.7RR's should easily pass emissions with those heads. The AFR's are emissions legal in the sense that they have thermactor capability which the Performer RPM's don't. The small AFR's (165 CC) should pass with the right cam and with cat H-pipe (of course), but they're an expensive choice even in a group purchase. I just bought a set so I should know. heh,heh,heh

03-12-2001, 08:24 AM	#8
Bangin Gears Guest Posts: n/a	Thanks for the suggestions, One last thing, i dont know much about roller rockers, but do you think a 1.7 set would be too much for the e303?

03-12-2001, 05:10 PM	#9
cojonepony Registered Member Join Date: Feb 2000 Posts: 132	Some people use the 1.7's with the E303, but in your case you might be better off with 1.6 ratio rockers since you're concerned about emissions. The E303 is borderline as it is when it comes to passing smog tests.