Hey --
I'm with you! I thought I had a 403 small block (SB) all along, then saw the
front distributor post thing goin' on here and wondered if I knew anything
at all.
I did find this site: http://www.442.com/oldsfaq/ofeng.htm clicked
on 1964 - 1990, looked at the casting engine number this morning and think
I'm a 403 kinda' guy.
For what its worth, we've driven many happy fun filled miles, got good
mileage for a motorhome, passed anything we wanted to (or should have) and
towed a VW thing at the same time.
I'm sure there's differences, (SB vs BB) but I'm a very happy camper. (and
driver).
Mark
'77 Kingsley ("set travel level to auto" version)
> -----Original Message-----
> From: owner-gmcmotorhome
> [mailto
wner-gmcmotorhome]On Behalf Of
> Gplymate
> Sent: Saturday, October 17, 1998 11:47 AM
> To: gmcmotorhome
> Subject: GMC: 403/455?
>
>
> I'm now in my third year of trying to figure out if I have a 403
> or a 455 in
> my 1978 Kingsley. Why I'm confused: First, I'm no expert at
> telling what an
> engine is by looking at it. Second, I'm a trusting soul. When I
> bought the
> coach it was alleged to have a 455 that had been installed as a
> replacement
> for the original 403 that was ruined on the delivery trip by a hot rodding
> young driver racing with another GMC being delivered from
> Pontiac, MI to the
> same destination (Eugene, OR) by an equally gregarious and competitive
> individual.
>
> Two years ago I visited Clasco and Golby and was given some
> instruction on how
> to tell a 403 from a 455. One of the clues was a visual difference in the
> right hand exhaust manifold. I looked at mine and sure enough,
> it had a 403
> manifold. Crap! I'd been deluded (I thought) by the story about
> the engine
> swap upon delivery. So, for the last two years, as my coach sat awaiting
> serious restoration I thought I had a 403 engine. Oh well, that
> didn't sound
> too bad since in the meantime I'd heard the 403 still has plenty
> of power and,
> besides, it gets better gas mileage.
>
> Then, a month ago I took the coach to Bob Fry near Portland to
> have him check
> it over and do what needed to be done to make it mechanically
> reliable. Bob
> took a look at the engine and pronounced it a 455; mostly based
> on the greater
> width of the intake mainifold. But, we also discovered some
> other anomallies,
> too. It has a Holley carburetor and a points distributor (no
> HEI). Those are
> gonna hafta be changed. But, one good thing; it has a 135 amp alternator,
> according to Bob. Also, now, it has the correct right hand 455 exhaust
> manifold (at a cost of $136 for parts plus $95 for labor).
>
> On this morning's Digest I saw Thomas Warner's post on how to you
> can tell a
> 455 from a 403. He said the distributor is on the back of a 455
> and on the
> front of a 403. Eureka, I thought! That makes identification as
> simple as it
> can get. Why didn't I find that out three years earlier? My
> distributor is
> on the back! Great! That proves I've got a 455. Or does it?
> Then, I saw
> Rick Staples' post, and he says the engines are the same with respect to
> location of the distributor. That put me right back to square one on
> confusion. I'm still not sure what I have. Can Thomas and Rick agree on
> where the distributor is supposed to be?
>
> One thing's for sure. The right hand manifold is different. It
> has a very
> constricted bend near the outlet. Bob says it's a real "valve
> burner" if you
> try to use one on a 455. Even I can tell the difference. The
> 455 manifold
> has an unobstructed outlet.
>
> Patrick, thanks for the post on your trip to Marion. I got some vicarious
> thrills from reading it. Maybe you'll have more to tell? Hope so.
>
> Glenn
> 78K (with a 403/455?)
>
I'm with you! I thought I had a 403 small block (SB) all along, then saw the
front distributor post thing goin' on here and wondered if I knew anything
at all.
I did find this site: http://www.442.com/oldsfaq/ofeng.htm clicked
on 1964 - 1990, looked at the casting engine number this morning and think
I'm a 403 kinda' guy.
For what its worth, we've driven many happy fun filled miles, got good
mileage for a motorhome, passed anything we wanted to (or should have) and
towed a VW thing at the same time.
I'm sure there's differences, (SB vs BB) but I'm a very happy camper. (and
driver).
Mark
'77 Kingsley ("set travel level to auto" version)
> -----Original Message-----
> From: owner-gmcmotorhome
> [mailto
wner-gmcmotorhome]On Behalf Of> Gplymate
> Sent: Saturday, October 17, 1998 11:47 AM
> To: gmcmotorhome
> Subject: GMC: 403/455?
>
>
> I'm now in my third year of trying to figure out if I have a 403
> or a 455 in
> my 1978 Kingsley. Why I'm confused: First, I'm no expert at
> telling what an
> engine is by looking at it. Second, I'm a trusting soul. When I
> bought the
> coach it was alleged to have a 455 that had been installed as a
> replacement
> for the original 403 that was ruined on the delivery trip by a hot rodding
> young driver racing with another GMC being delivered from
> Pontiac, MI to the
> same destination (Eugene, OR) by an equally gregarious and competitive
> individual.
>
> Two years ago I visited Clasco and Golby and was given some
> instruction on how
> to tell a 403 from a 455. One of the clues was a visual difference in the
> right hand exhaust manifold. I looked at mine and sure enough,
> it had a 403
> manifold. Crap! I'd been deluded (I thought) by the story about
> the engine
> swap upon delivery. So, for the last two years, as my coach sat awaiting
> serious restoration I thought I had a 403 engine. Oh well, that
> didn't sound
> too bad since in the meantime I'd heard the 403 still has plenty
> of power and,
> besides, it gets better gas mileage.
>
> Then, a month ago I took the coach to Bob Fry near Portland to
> have him check
> it over and do what needed to be done to make it mechanically
> reliable. Bob
> took a look at the engine and pronounced it a 455; mostly based
> on the greater
> width of the intake mainifold. But, we also discovered some
> other anomallies,
> too. It has a Holley carburetor and a points distributor (no
> HEI). Those are
> gonna hafta be changed. But, one good thing; it has a 135 amp alternator,
> according to Bob. Also, now, it has the correct right hand 455 exhaust
> manifold (at a cost of $136 for parts plus $95 for labor).
>
> On this morning's Digest I saw Thomas Warner's post on how to you
> can tell a
> 455 from a 403. He said the distributor is on the back of a 455
> and on the
> front of a 403. Eureka, I thought! That makes identification as
> simple as it
> can get. Why didn't I find that out three years earlier? My
> distributor is
> on the back! Great! That proves I've got a 455. Or does it?
> Then, I saw
> Rick Staples' post, and he says the engines are the same with respect to
> location of the distributor. That put me right back to square one on
> confusion. I'm still not sure what I have. Can Thomas and Rick agree on
> where the distributor is supposed to be?
>
> One thing's for sure. The right hand manifold is different. It
> has a very
> constricted bend near the outlet. Bob says it's a real "valve
> burner" if you
> try to use one on a 455. Even I can tell the difference. The
> 455 manifold
> has an unobstructed outlet.
>
> Patrick, thanks for the post on your trip to Marion. I got some vicarious
> thrills from reading it. Maybe you'll have more to tell? Hope so.
>
> Glenn
> 78K (with a 403/455?)
>
