Converting a Mopar 440 to GM TBI translated

[rr]

In all honesty this is probably true. The killer is not having a hac. Me, I have enough
trouble getting'em tuned even knowing where the tables are and what they do. . .

BobR.

Squash wrote:

> Maybe using the 94/95 truck ECM would be a good idea?  TBI, P4, 32 BLM cells, etc.  Would be
> easier to get feedback from the ECM i'd think.
>
> Squash
>
> --- Shannen Durphey <shannen at grolen.com> wrote:
> > Don't forget the little 2.8 tbi.  It's got reeealy tiny bores.
> >
> > The tbi used on the 454 is small for the engine's size.  Using something smaller
> > still would reduce the overall power made by the engine.  Your 440 may truly suffer
> > if you were to use a tb sized for a small block engine.  The actual hp rating of
> > the tbi 454 is around 220.  With a 350 sized TB, you likely won't draw enough air
> > into the engine to generate numbers that high.
> >
> > One option is to find someone with access to a machine shop and see if you can get
> > the throttle bores machined larger.
> >
> > There are adapters available from Holley and GM (and maybe others) which will allow
> > the throttle body to be bolted to a 4bbl manifold.  The GM part is fairly spendy if
> > purchased through the dealership.
> >
> > You migh consider using a Chrysler electronic ignition distributor with a GM
> > ignition module.  You will need to permanently prevent the vacuum and mechanical
> > advance mechanisms from moving in order to take advantage of the ecm;s ability to
> > adjust spark timing.
> >
> > Beyond any doubt, the best ecm to use is the 1227747, which was used in most 8 cyl
> > tbi pickups, and some 4.3 v6 applications.  Search the gmecm home page, there's a
> > ton of info about it, and there are many free tools to help tune it when you're
> > ready.
> >
> > Cadillac tbi systems can have subtle differences from other GM systems.  Sometimes
> > they have no IAC to control idle speed, but use an external motor to open the
> > throttle.  This scheme is not designed to work with a "regular" GM tbi ecm.  I have
> > not heard of anyone adapting the Caddy system for use with a 7747 or one of its
> > cousins.
> >
> > Download and look through the diy-efi archives.  There are plenty of war stories
> > and more than a few different versions of this same question there.  You'll find
> > more information than you want to know, and you'll probably end up with a few new
> > ideas before you're done.
> >
> > But by far, the best answer for the simplest swap is to locate a complete TBI
> > equipped 454 and get all your parts in the same place.  Any other option involves
> > more time, effort, and research.
> >
> > Shannen
> > My clock says 8:36pm...
> >
>

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