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