GT-40 iron heads

-RootS- · 03-31-2003, 08:52 PM

What do you think of the gt-40 iron heads ? I have a 351 windsor(1969) with original heads and I would like to know if it would be a good idea to get those head, I can have them pretty cheap. It's a street car, I'm looking for good performance without hurting the streetability of the car and I don't have the money for aluminium heads.

erikd93lx · 03-31-2003, 10:38 PM

I am not clear what you mean. Are you trying to decide between GT40 heads and the '69 Windsor heads? If you are talking about the heads on the '69, they are most likely DOOE heads. The DOOE's are very similar to the Iron GT40's, but you would need to do some work to them for them to work properly on a newer car. The '69 was probably made to run leaded gas, so you would need different valves, retainers, etc. Also, the '69 heads have no emmissions on them like the GT40's, another thing is the size of the bolts, you would have to buy special bolts to put the 351W heads on a 302, I think summitt sells them. I personally have a set of DOOE's that have been worked on alot to put on a 5.0 HO but I didn't do the work myself so I can't say for sure exactly what has been done. I know they made my friends car run mid 11's with 9 pounds of boost though so they are good heads.

Coupe50h · 03-31-2003, 10:46 PM

I seen the 69 windsors do pretty good, one car i saw at the track had a stock intake ported, the 69 heads, e-cam retard4 degrees, longtubes ect...went 12.60's at 114 mph

i know that mph is crazy!

-RootS- · 04-01-2003, 08:45 PM

I already have the 69 heads on my 351, my best time to date 12.60 at 113 mph with 125 hp on nos (nitrous in 2 and 3 gears without powershifting). I know I'm only using about 70 hp of the nirous because of the restriction of the 69 heads and I would like to know if the gt-40 "P" iron heads could help me. Is there a big difference between the gt-40 "p" and the 69 heads, will the gt-40 heads give me all the hp of the nitrous ?

srv1 · 04-01-2003, 08:50 PM

all i can say about the "P" heads is that they are roughly 58cc, outflow the GT40 heads and have better combustion chamber design. The drawback is you have to use special headers and that could be a pain. I just bought mine and i am going to put mine on soon. If your staying NA, shave them if you are running stock pistons(depends on what you have though). I will be shaving mine .030" and running an E cam hopefully. This is all trial and error for me.

James

erikd93lx · 04-01-2003, 10:46 PM

You will most likely not see any gain at all in using GT40 P heads over the '69 heads you already have. If the '69 heads you have are worked over at all, they are better. If they are still stock, then they are about the same. The GT40 heads(P or not) are based off of the heads you are currently running(assuming they are DOOE heads). Flow numbers will be very similar between them, and even if the GT40P's are better, they aren't better enough to justify spending all the gasket money and labor time to change them! Your best bet would be to get some good aluminum heads(ex. Trick Flow).

03-31-2003, 08:52 PM	#1
-RootS- Registered Member Join Date: Sep 2001 Location: Lévis, Québec, Canada Posts: 12	GT-40 iron heads What do you think of the gt-40 iron heads ? I have a 351 windsor(1969) with original heads and I would like to know if it would be a good idea to get those head, I can have them pretty cheap. It's a street car, I'm looking for good performance without hurting the streetability of the car and I don't have the money for aluminium heads.

03-31-2003, 10:38 PM	#2
erikd93lx Registered Member Join Date: Dec 2002 Location: Terrytown, La. Posts: 18	I am not clear what you mean. Are you trying to decide between GT40 heads and the '69 Windsor heads? If you are talking about the heads on the '69, they are most likely DOOE heads. The DOOE's are very similar to the Iron GT40's, but you would need to do some work to them for them to work properly on a newer car. The '69 was probably made to run leaded gas, so you would need different valves, retainers, etc. Also, the '69 heads have no emmissions on them like the GT40's, another thing is the size of the bolts, you would have to buy special bolts to put the 351W heads on a 302, I think summitt sells them. I personally have a set of DOOE's that have been worked on alot to put on a 5.0 HO but I didn't do the work myself so I can't say for sure exactly what has been done. I know they made my friends car run mid 11's with 9 pounds of boost though so they are good heads. __________________ '93 lx---built 331 and a bunch of stuff(gone but not forgotten) '94 white lightning, #2443 of 4007, built on april 27th, 1994. JET chip and a K&N my ride: http://community.webshots.com/album/36965548zRfjyB

03-31-2003, 10:46 PM	#3
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	I seen the 69 windsors do pretty good, one car i saw at the track had a stock intake ported, the 69 heads, e-cam retard4 degrees, longtubes ect...went 12.60's at 114 mph i know that mph is crazy! __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

04-01-2003, 08:50 PM	#5
srv1 Get down..... Join Date: Apr 2001 Location: Room 103 Posts: 2,095	all i can say about the "P" heads is that they are roughly 58cc, outflow the GT40 heads and have better combustion chamber design. The drawback is you have to use special headers and that could be a pain. I just bought mine and i am going to put mine on soon. If your staying NA, shave them if you are running stock pistons(depends on what you have though). I will be shaving mine .030" and running an E cam hopefully. This is all trial and error for me. James __________________ Cobra brakes are on! Finally..... ------------------------------------------------

04-01-2003, 10:46 PM	#6
erikd93lx Registered Member Join Date: Dec 2002 Location: Terrytown, La. Posts: 18	You will most likely not see any gain at all in using GT40 P heads over the '69 heads you already have. If the '69 heads you have are worked over at all, they are better. If they are still stock, then they are about the same. The GT40 heads(P or not) are based off of the heads you are currently running(assuming they are DOOE heads). Flow numbers will be very similar between them, and even if the GT40P's are better, they aren't better enough to justify spending all the gasket money and labor time to change them! Your best bet would be to get some good aluminum heads(ex. Trick Flow). __________________ '93 lx---built 331 and a bunch of stuff(gone but not forgotten) '94 white lightning, #2443 of 4007, built on april 27th, 1994. JET chip and a K&N my ride: http://community.webshots.com/album/36965548zRfjyB

04-01-2003, 08:45 PM	#4
-RootS- Registered Member Join Date: Sep 2001 Location: Lévis, Québec, Canada Posts: 12	I already have the 69 heads on my 351, my best time to date 12.60 at 113 mph with 125 hp on nos (nitrous in 2 and 3 gears without powershifting). I know I'm only using about 70 hp of the nirous because of the restriction of the 69 heads and I would like to know if the gt-40 "P" iron heads could help me. Is there a big difference between the gt-40 "p" and the 69 heads, will the gt-40 heads give me all the hp of the nitrous ?

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