560 Throttle Body onto 6.9

[john erbe]

Having read some past posts I believe some of you have done this and could answer some questions as I have started the project having just pulled the TB from a wrecker 560. Aware that I've got to machine a larger bore on the 6.9 intake manifold but, what about the top end, can the port on the underside of the 6.9's air/fuel manifold be enlarged or do I need to bring over the whole 560 set-up? I note that the latter's belly is plastic as opposed to metal on the 6.9.

 

[Oversize]

Isnt it a flexible connection? I've heard u need an aftermarket hose... Any pix of the parts involved?

 

[john erbe]

It's a flexible connection on the 560 but I haven't taken opened up the 6.9 yet. Should it also be flexible, can it accommodate the bigger bore is the question. Hoping someone would know as that would make things much easier.

 

[motec 6.9]

Hi John yes it is a flexible hose between the 2. Fuel distributor has just under 90mm opening underneath so not a problem . You can use a silicon turbo hose as the connector. like when I fitted 92mm LS throttle body.

 

[john erbe]

Oversise and others, I've attempted to attach photo of the underside of the air intake/fuel distributor of the 560. If I've failed, check my recent post of the same topic on the M-100 website, where the photo shows. Now, some questions: Referring to the port with the flex fitting as you call it, shown in the photo, which comes down on the TB, does that same port on the corresponding manifold of the 6.9 have sufficient aperture to accommodate the larger bore of the 560 TB? In brief, what parts in addition to the electrical connector(s) do I need to bring over from the 560? Also, are the bolt patterns of the TBs the same, and lastly, will the single snorkel air filter of the 6.9 meet the increased demand? Thanks.

 

[john erbe]

Thanks Motec. Our replies must have crossed.

 

[motec 6.9]

All good stock Euro with 8.8 comp made 230.1 hp at rear wheels . I made 255.6 hp with 2.5 inch duel exhaust and x pipe and custom ceramic coated extractors/Headers to you John. Made around 20hp more with 92mm LS throttle but due to shaft being 25mm to high car was un driveable lift throttle it closed plate. I have since has 3 85mm throttle bodies made they are cad scans off factory 65mm throttle body . They will go on and be dynode once car is out off paint shop and Franken CIS will be fitted at the same time. Will move battery to fit 560 air cleaner have 560SL air horn to fit replaces smaller air horn so they are both same size.

 

[john erbe]

Looks good Motec. Unfortunately here in California we've got to deal with state emission tests so your dual set-up mod would be considered "tampering" and thusly taboo.

 

[john erbe]

For anyone else thinking about going down this road, TB bolt patterns not the same.