i bought the au series 3 manifolds for my ef xr8. already got the gt40p heads in it. i was wondering for installing the manifolds, the way people describe it i thought it was bolt on dont need to do any changes, i know i have to get a bigger throttle body and maf once i get them how do i go about putting them all in? is it simple to do at home? or would i need to take it somewhere? is there other parts that need changing or ?
thanks

In terms of matching pieces for maximum effect, the Explorer usually had a 65mm TB and I think the 70mm MAF. That along with the GT40P heads is pretty much what the AU XR8 engines had - other than their particular cam. However, you can choose a cam that you like and add some roller rockers ( 1.6 or 1.7 depending on your choice of cam ) and away you go.

how much did it cost ya for the upper and lower manifold?

If you're somewhat mechanically minded, these mods you can do at home. If you have a mechanic mate, then even better.

One important thing you'll need to do is relocate the intake air temp sensor to the intake piping. It'll currently be located in the lower intake manifold, next to runner 5, but the AU lower doesn't have a hole in that location.