Will the 4.6 manifold fit on a 5.4 manifold?

[royb]

I'm wanting to put the 5.4 block & heads in the 05 GT and need to know if the 4.6 manifold will fit on the 5.4 block & heads. I want to put my o5 gt Saleen Supercharger on it that's why I need to know if the ports line up the same.

 

[oohsoobad2]

The 4.6 manifold will not directly bolt up. This is because the 5.4 is tall which makes the ports further apart. What people have been doing with 2V and 4V 5.4 swaps is using intake adatpers, but I havent seen a set for the 3V heads yet.

 

[crash]

Right. The 5.4 deck height is taller, which mounts the heads higher and further apart.

The aftermarket has the DOHC engines covered by Sullivan, however, the 4.6 and SOHC engines (At this point) require custom intakes from Hogan or building your own.

DOHC: Sullivan Performance cast single plane intakes... $600, but requires their rails and if you run a single Cobra or Lightning TB, you need the 90 degree adapter. A 4 blade TBI type TB is available as well, for use N/A or with a carb hat for blowers and turbos. Adapters are at an additional cost.

http://www.sullivanperformance.com/index.htm (DOHC and soon to have M-112 castings available as well).

I AM in contact with a few manufacturers and they ARE working on them, but to my knowledge, not soon.

Hogans: CUSTOM intakes. ($1200-3200)

http://www.hogansracingmanifolds.com/

I know Sullivans stuff well, however, just got docs on the Hogans. Go over the site to see what they can build. QUALITY does not come cheap. These are sheet metal, NOT castings.

 

[delurker]

I'm guessing that's why Saleen is sticking with a forged-internals 4.6 for the "Extreme" - currently no way to mount the Series VI blower on the larger blocks due to the intake ports being further apart without some R&D to make adaptors or modify the runners.

 

[crash]

There ARE adapters (4.6 to 5.4, not the other way around), just can't remember the link right now.