advice: 403 vs 455 ???

j fleming

New member
Aug 14, 2000
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I have begun the hunt for a gmc and was wondering if
there were any major differences between the two
engine options. For example power for towing or
getting over the mountains, milliage, reliabillity, or
are the differences minor enough that engine size
should not be a factor when looking for a unit.

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J,

I've never heard anyone with a 403 complain about it. Down where these
engines live(under 3,000 rpm) there ain't much difference in HP/torque
between the two and the 403 is slightly more fuel efficient.

My $.02,
Patrick

>
> I have begun the hunt for a gmc and was wondering if
> there were any major differences between the two
> engine options. For example power for towing or
> getting over the mountains, milliage, reliabillity, or
> are the differences minor enough that engine size
> should not be a factor when looking for a unit.
 
On Wed, 16 Aug 2000 04:30:01 -0700 (PDT) j fleming
writes:
> I have begun the hunt for a gmc and was wondering if
> there were any major differences between the two
> engine options. For example power for towing or
> getting over the mountains, milliage, reliabillity, or
> are the differences minor enough that engine size
> should not be a factor when looking for a unit.
>

You will undoubtedly solicit strong opinions either way as we tend to
believe whatever we currently have is the Best!

I would pay more attention to other factors such as year of mfg. There
were important improvements made in areas as dash air con distribution,
etc that would tend to suggest late 77 and 1978 models are better
investments however the oem engine was a 403ci. This is not necessarily
detrimental, especially in the 23' model.

My opinion....I have an early 77 that has the a/c improvements and the
403 has been replaced with a 455!

David Lee Greenberg
GMC Motorhome Registry
Dedicated To The Preservation Of The GMC Classic!
www.gmcss.com/registry.htm
 
Hi All

Did someone say a while ago that there is a port fuel injection manifold
that will fit the 403 but not the 455. Maybe a '85-'90 307 manifold.

I would think that a 403 with multi-port fuel injection might be a better
choice than a 455 with a quadrajet or maybe even a 455 with TBI.

Dave Mumert

----- Original Message -----
From:
To:
Sent: Wednesday, August 16, 2000 6:37 AM
Subject: GMC: advice: 403 vs 455 ???

> On Wed, 16 Aug 2000 04:30:01 -0700 (PDT) j fleming

> > I have begun the hunt for a gmc and was wondering if
> > there were any major differences between the two
> > engine options. For example power for towing or
> > getting over the mountains, milliage, reliabillity, or
> > are the differences minor enough that engine size
> > should not be a factor when looking for a unit.
> >
>
> You will undoubtedly solicit strong opinions either way as we tend to
> believe whatever we currently have is the Best!
>
> I would pay more attention to other factors such as year of mfg. There
> were important improvements made in areas as dash air con distribution,
> etc that would tend to suggest late 77 and 1978 models are better
> investments however the oem engine was a 403ci. This is not necessarily
> detrimental, especially in the 23' model.
>
> My opinion....I have an early 77 that has the a/c improvements and the
> 403 has been replaced with a 455!
>
> David Lee Greenberg
> GMC Motorhome Registry
> Dedicated To The Preservation Of The GMC Classic!
> www.gmcss.com/registry.htm
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: gmcmotorhome-unsubscribe
> For additional commands, e-mail: gmcmotorhome-help
>
 
Yep - details are in the Olds FAQ at:

http://www.inil.com/users/dlbrown/ofinm.htm 1964 - 1990 Oldsmobile Port
Fuel Injection

That long URL prolly won't come thru right so you'll have to cut 'n paste
into your brower's address window.

Patrick

>
> Did someone say a while ago that there is a port fuel
> injection manifold that will fit the 403 but not the
> 455. Maybe a '85-'90 307 manifold.