New motor for my 88

Well heres the deal I have a 88 gt 5.0 with a decent 302 in it but I want a fresh motor and little more power. One of my friends who has built alot of fords has a 351w bottom end with a nice streetable cam (not sure what specs), a high flow oil pump and soon to have a new crank because the one in it the harmonic balancer got loose and striped the bolt hole, so it would have to be machined, he has low compression pistons because orginaly he was gonna put a blower on it but didnt, (I wanna go with some affordable flat top pistons being that I am a student) I can get this whole thing for 300 because I'm a friend and he got a heck of a deal on another motor he is gonna build. Well for now im gonna have to go with my 302 heads till I can afford some gt40 heads, But I guess the whole reason behind me putting this here is that I know I need a diffrent intake manifold to fit because the one he has wont fit clearance wise with my carb. What kind of manifold should i use, right now I have a edlebrock on my 302 will it work?

Also while Im writing a thread my stang is an 4 speed aod and when I have it in one I will run to about redline then hit it to the next "gear" but it shifts twice do I have a problem or do I need to just keep on it and it will shift on its own. (never owned an auto sports car)

The tranny will shift on its own.

The 302 intake wont work, the 351w has a higher deck height so the 351 intake is a little wider.

If you reuse your stock 302 heads you will have to have the bolt holes drilled out to 1/2". The 351w is drilled & tapped for a 1/2" bolt where the 302 uses a 3/8" head bolt. So you will need the bolt holes in the 302 heads drilled out to accept the 1/2" windsor head bolt. I'd suggest atleast an Edelbrock Performer intake for the 351w.

For the Pistons just get some Speed Pro hyper's. I would strongly suggest that you stay away from the cheap Keith Black hyper's.