Running a 305 with '747

[Shannen Durphey]

Kurek, Larry wrote:
> 
> All:
> 
> I am considering swapping a 305 motor into my 87 Astro van. It currently has
> a 4.3 TBI setup on it, and I am debating what system to run on the 305. It
> currently has a TPI setup on it, but I don't feel like wasting that system
> on a minivan :)  So...I have a complete TBI setup off a 1500 truck (747),
> which as I can see...is pretty much plug and play with the Astro wiring
> harness (granted, a couple of repins...but no biggie). The biggest thing I
> see, is recalibrating everything to run as an 8cyl vs a 6. Easiest thing
> here is to run the 747 ECM rather than the Astro's. However, the 747 is
> calibrated for a 350. What, if anything, should I do to run this on a 305? 
Uhh...
Ummm...
Well...
The astro uses a 1227747, the same ecm used for tbi trucks from 4.3l
all the way up to 454 ci.
The calpack is different between the smallblock v-8 and the 4.3l.
Enough said??
Shannen
I
> know the ECM will "learn" through O2 feedback, however I'd rather start with
> a decent calibration that was relatively close to begin with. I was
> considering: A new PROM with a modified cylinder size (easiest?); or a
> ECM/PROM/Cal from a 305 TBI engine (Know of any that would be useful?).
> 
> Any help much appreciated :)
> 
> Larry
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