Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec 95 Contour SE 2.5 to 3.0 duratech swap

So I'm assuming you want to do a 3.0 swap and want to use your 2.5L lower intake system.

This has been done multiple times by modifying the heads. The modification that needs to be performed is caused by the different placement of the fuel injectors in the different engines and by the port shape.

01+ engines (and maybe some 00s) use oval ports with injectors mounted in the center of the port.

All 2.5L engines in the contour/cougar/mystique will use a split port intake system, or dual-runner intake system with the injector mounted only in the left (primary) intake port.

So what you are doing is taking a lower intake manifold meant for a split port head and bolting it to the oval port head. The bolt holes line up but the injector mounting point in the lower intake manifold is aimed at a bit of solid metal in the head since the split port intake overlaps the oval port head port.
Additionally, the oval port injector mounting point requires a "V" shaped valley in the head to accomodate the spread of the injector spray. That valley is not overlapped and will leave a small hole that will leak air if not filled in. This is the part that needs to be filled with epoxy.

Some people take the heads and get that portion filled in with an aluminum weld by a welder, then they use a die grinder with cutting bit and shape the weld area as well as the intake holes to fit the split port intake. That is the best idea but may run you $50-$125 depending.
You still need the die grinder and to cut the stuff, but you will only spend $5 on brake parts cleaner and JB Weld Qwik epoxy to fill it yourself as well and it will be ready to work in about 10 minutes. That means no shop turnaround time. Reliability of the epoxy filler method is still 100% so far so I wouldn't worry about that.

I made a sketch that I will host in a moment.

After you make this conversion then you have just changed the engine to a 3.0 that fits your 2.5L stuff, a long-block hyrbrid if you will.

Then you will have to deal with amount of fuel that the 95 can deliver to the engine but that is something that can be dealt with later.