Maybe there is holes drilled in the rear I have not seen yet, But I am putting this on a 6er with a little power adders its not a GT so I do not know of the rear frame if differefnt because of the 7.5. Maybe thats why I did not see any holes pre drilled but they might be there and I am blind I was told that the upper attachments for a quad shock is on the 6ers but I just have to weld the plate to my axle housings on due to the 8.8 and 7.5 difference. When all is said and done I should have about 290hp ?tq thats n/a coming pretty soon hopefully. Then 4.2 stroker time add another 40 to both after a certain mileage probably 100,000. And if money allows at that point a turbo. I dont see why so much complaining about them if there on the 03-04 cobras pupming out asz loads of power and torque. Barnaby thanks for the info to the actual question Ateup the reason I was thinking of welding as well is for added strength and piece of mind. I do agree full lenthgs are cheap but these are from Ford and I am Ford Racing perfomance parts man. And in the end for resale value these look better they go with the curve of the floor pan and frame and are a Ford item not considered a racing add on. Thanks for the input.