GT40 or 351 Heads

I have a set of D90E 351 Windsor heads that I have been contimplating putting on my 88. They already have screw in studs, dual valve springs, and a small amount of port work. Are there any advantage over putting these on my 302 as opposed to a set of GT-40 irons? The 351 heads valve size is the same as the GT-40's. But I would also like to know the CC chamber sizes of both, intake and exhause runner length of each and so forth to help aid me in a decision. If it is a worthwile swap over the other iron heads I will go ahead and finish any port work they may need and bolt them on. I know I will need different bolts or to use the special washers, but do I need a special length pushrod and what rocker arms will i need to use? Thanks

I'm trying to get a little bit more expierenced feedback. I still need some specs on each head and user testimonials of both also. Thanks.

N8Miller said:

since your looking for more "experienced" testimony, i would tell you that after researching the gt40 cobra heads, i have found that they will take you into the mid-12s and not have any problems. they are a good "bang for the buck" head and will produce HP in the high-200s to the low 300s depending on setup. They also make great heads for power adders and some people that replied to a previous post of mine said that they have gone 11s with some good boost.

Click to expand...

Ok then. Maybe what I need is the structural differences besides the head bolt holes, CC size, port length and volume etc?

notchback said:

they are almost identical, but you will need to get hardened valve seats for the "dooe"'s....and you did misread that casting number right....it is DOOE no "9"?

those are what the gt-40's were based on

and btw...my buddy went 11.20's on gt40 irons mild port, stock gt40 intake and 150 shot ..............he may have broke into 10's i don't recall

Click to expand...

Yeah, DOOe's. That was a mistype. And yes, I need to check if they have hardened valve seats installed yet. They were on a 66 302 coupe doing 12's in the 1/4. They were a buddys of mine that has long moved away.