V6 TBI Vesrus V8 TBI

[John Zarli]

Hlynur Tomasson wrote:
> 
> John Zarli wrote:
> >
> > Hlynur Tomasson wrote:
> > >
> > > Has anyone ever swaped a 4.3 V6 TBI for a 350/350 V8 in a Chevy truck,
> > > if so could you tell me if some or all (including computer & sensors) of
> > > the TBI system from the V6 can be used on the 350 engine.
> > > Thanks in advance
> > > H. Tomasson
> > Hlynur, I'm about 2 weeks away! The V8 engine is built except for some
> > Crane roller rockers that should arrive Monday.  The significant
> > differences are that the motor mounts are in different positions
> > relative to the transmission. Same distance from front of motor, less
> > those 2 pistons. Electrically the engines are identical save for the
> > memcal & eprom that plug in to the cpu. The V6 has smaller injector
> > ratings.  Most 88(?) & up V6 have  hydraulic roller lifters for thecam
> > vs the plain old hydraulic lifters in the V8's. The motor I have built
> > uses a larger 2" bore from a big block TBI, along with a ZZ3 hydraulic
> > roller cam. If it works out, I'll probably be bragging all over the
> > internet.....if not I'll probably be begging for help all over the
> > internet.(g)..Stay tuned.
> Thank you for your input,
> The truck I'm dealing with is 1992 Astro Van. My plan is to buy a new
> 350/350 for the Astro. At this moment my main concern is the setup for
> the TBI, witch components I can recycle from the V6 4.3L engine & what I
> have to buy additionally.
> Are you saing that the computers are identical V8 & V6?
> Are you building your engine from scratch by some special recipe? Please
> tell me more about your setup.
> H. Tomasson
Hlynur, great minds think alike (g) as a matter of fact the vehicle I
will be swapping into is an 89 Astrovan. I have confirmed the
similarities through 1991 by examination of friends trucks, etc. Many
parts listings seem to leave off at year 1991, so I can not confirm
first hand the CPU in your 1992. I also have a 1994 Astro, so I can
confirm that mechanical clearances all seem to be the same as my 89, but
the 94 has the strong 200HP CPI engine, & everything is different.  The
ECM on Astrovans is located on the passenger side just in front of the
door. It is behind a kick panel that is held on with a screw hidden in
the carpet & a couple of those obnoxious interior clips that GM seems to
love. The CPU number for an 88 350, 89 4.3 & 91 305  TBI engine that I
have looked at is 1227747. It seems pretty standard.  My engine started
as a 1988 4 bolt core that I got from a local shop for $350, had it
bored +.030. Got lucky finding the oversized throttle body for $40,
which I have tried on another running truck without any trouble. The
rest of the parts are  new from Competition Products, Fuel Injection
Specialties, Summit, Jegs, Northern Auto Parts, Discount Auto
Parts,etc.  ( whew! Everybody got a piece of the pie). As for the
recipe, it is a mix of best prices combined with my insistence on trying
the hydraulic roller lifters. perhaps we should wait a few more weeks to
see how it turns out.