Home » Public Forums » GMCnet » Re: [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's
| Re: [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's [message #342855] |
Fri, 26 April 2019 14:14  |
BobDunahugh
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
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The hardest things on any engine are. Lost's of cold starts, short trips, and luging with too much throttle. Our GMC's have few cold starts as to miles driven. Not much for short trips. And get a 3:70 final drive. With standard 10W-30 oil/filter changes in the range of 3000 miles. Plastic timing gear changed out. Howell/GM EFI helps a lot. 200,000 shouldn't be a problem. I have the 403 that came out of our burned 78 GMC. Has never been apart except for the plastic cam gear replacement. Idle oil pressure hot is just under 30 PSI. Compression readings 140 to 145 PSI. ( New 150 to 155 PSI.) Used a qt of oil in 2500 miles. And has 154,000 miles on it. And I'm looking for another GMC to put that 403 in. Our present 78 Royale, 403, gets lots of oil changes. 3:70 FD, and a Howell/GM EFI. Bob Dunahugh
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| Re: [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's [message #342857 is a reply to message #342855] |
Fri, 26 April 2019 15:50  |
johnd01
Messages: 354
Registered: July 2017
Location: Sacrameot
Karma: -1
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What RPM do you need to be above to not be lugging at full throttle?
John Phillips
75 Avion VIN A26000
Retired
Rancho Cordova, CA 95670
On Fri, Apr 26, 2019 at 12:15 PM Bob Dunahugh via Gmclist <
gmclist@list.gmcnet.org> wrote:
> The hardest things on any engine are. Lost's of cold starts, short
> trips, and luging with too much throttle. Our GMC's have few cold starts as
> to miles driven. Not much for short trips. And get a 3:70 final drive.
> With standard 10W-30 oil/filter changes in the range of 3000 miles.
> Plastic timing gear changed out. Howell/GM EFI helps a lot. 200,000
> shouldn't be a problem. I have the 403 that came out of our burned 78 GMC.
> Has never been apart except for the plastic cam gear replacement. Idle oil
> pressure hot is just under 30 PSI. Compression readings 140 to 145 PSI. (
> New 150 to 155 PSI.) Used a qt of oil in 2500 miles. And has 154,000 miles
> on it. And I'm looking for another GMC to put that 403 in. Our present 78
> Royale, 403, gets lots of oil changes. 3:70 FD, and a Howell/GM EFI. Bob
> Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
*John Phillips*
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Johnd01
John Phillips
Avion A2600 TZE064V101164
Rancho Cordova, CA (Sacramento)
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| Re: [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's [message #342860 is a reply to message #342857] |
Fri, 26 April 2019 18:18 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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If you can add more throttle, and the vehicle easily gains speed (rpm)
then, you more than likely are not lugging the engine. If you cannot gain
speed by pressing harder on the accelerator, you are more than likely
lugging the engine. Cure? Downshift into a lower gear.
Jim Hupy
Salem, Or
On Fri, Apr 26, 2019, 3:17 PM John Phillips via Gmclist <
gmclist@list.gmcnet.org> wrote:
> What RPM do you need to be above to not be lugging at full throttle?
> John Phillips
> 75 Avion VIN A26000
> Retired
> Rancho Cordova, CA 95670
>
> On Fri, Apr 26, 2019 at 12:15 PM Bob Dunahugh via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> The hardest things on any engine are. Lost's of cold starts, short
>> trips, and luging with too much throttle. Our GMC's have few cold starts
> as
>> to miles driven. Not much for short trips. And get a 3:70 final drive.
>> With standard 10W-30 oil/filter changes in the range of 3000 miles.
>> Plastic timing gear changed out. Howell/GM EFI helps a lot. 200,000
>> shouldn't be a problem. I have the 403 that came out of our burned 78
> GMC.
>> Has never been apart except for the plastic cam gear replacement. Idle
> oil
>> pressure hot is just under 30 PSI. Compression readings 140 to 145 PSI. (
>> New 150 to 155 PSI.) Used a qt of oil in 2500 miles. And has 154,000
> miles
>> on it. And I'm looking for another GMC to put that 403 in. Our present
> 78
>> Royale, 403, gets lots of oil changes. 3:70 FD, and a Howell/GM EFI.
> Bob
>> Dunahugh
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
> --
>
> *John Phillips*
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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| [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's [message #342873 is a reply to message #342855] |
Sat, 27 April 2019 01:16 |
BobDunahugh
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
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Senior Member |
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My 425 trans/3:70 have been in service since 2003. In two different 78 Royales. I personally rebuilt it in that year. And now have 87,000 miles on the pair. We've gone on one trip in all those years without towing something. Thus my lowest GVW all that time. Comes in at 17,000 lbs. When I'm towing my 24 ft trailer enclosed trailer. That has a shop/Yenko in it. My GVW comes in at just under 25,000 lbs. And all this with a 403. I don't use any synthetic oil/fluid/lubes. Never let the engine oil/filter go more the 3,000 miles. Change trans fluid every year. FD, and power steering fluid every other trans fluid change. I strongly believe that changing oil/fluids is the key to longevity. Over the use of synthetics. Oils CHEEP. Not rebuilds. So if there's a GMC out there that gets REALLY loaded. I think that ours is at the top. I have one rule that I believe in. Never use more the half throttle while pulling long steep grades. And DO NOT care how fast I'm going. Bob Dunahugh 78-403 Royale.
________________________________
From: Bob Dunahugh
Sent: Friday, April 26, 2019 2:14 PM
To: gmclist@list.gmcnet.org
Subject: RE: The Olds 403/455 were an outstanding choice for our GMC's
The hardest things on any engine are. Lost's of cold starts, short trips, and luging with too much throttle. Our GMC's have few cold starts as to miles driven. Not much for short trips. And get a 3:70 final drive. With standard 10W-30 oil/filter changes in the range of 3000 miles. Plastic timing gear changed out. Howell/GM EFI helps a lot. 200,000 shouldn't be a problem. I have the 403 that came out of our burned 78 GMC. Has never been apart except for the plastic cam gear replacement. Idle oil pressure hot is just under 30 PSI. Compression readings 140 to 145 PSI. ( New 150 to 155 PSI.) Used a qt of oil in 2500 miles. And has 154,000 miles on it. And I'm looking for another GMC to put that 403 in. Our present 78 Royale, 403, gets lots of oil changes. 3:70 FD, and a Howell/GM EFI. Bob Dunahugh
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| Re: [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's [message #342883 is a reply to message #342873] |
Sat, 27 April 2019 11:43 |
BobDunahugh
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
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Senior Member |
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Matt said it perfectly on the FD. Not a weak part. Just the wrong part. To me. Jim K's 3:70 FD is a great ratio. Towing or NOT. The 3:55 to 3:21 do help some. I see it that. If your spending the money. Why not get the most benefit from that cash outlay. Want to take the most load off your trans. And have it run cooler? The 3:70/4:10 will do it. And the power drive does nothing beneficial for the trans. That's a fact. It just makes it easier to put more load on the trans. After installing the 3:70. Gas mileage went up due to running a higher intake vacuum. I'll get off my box now. ( Grin.) Want to keep me off my box? Don't talk about drivetrain components. Bob Dunahugh 78 Royale
________________________________
From: Bob Dunahugh
Sent: Saturday, April 27, 2019 1:16 AM
To: gmclist@list.gmcnet.org
Subject: The Olds 403/455 were an outstanding choice for our GMC's
My 425 trans/3:70 have been in service since 2003. In two different 78 Royales. I personally rebuilt it in that year. And now have 87,000 miles on the pair. We've gone on one trip in all those years without towing something. Thus my lowest GVW all that time. Comes in at 17,000 lbs. When I'm towing my 24 ft trailer enclosed trailer. That has a shop/Yenko in it. My GVW comes in at just under 25,000 lbs. And all this with a 403. I don't use any synthetic oil/fluid/lubes. Never let the engine oil/filter go more the 3,000 miles. Change trans fluid every year. FD, and power steering fluid every other trans fluid change. I strongly believe that changing oil/fluids is the key to longevity. Over the use of synthetics. Oils CHEEP. Not rebuilds. So if there's a GMC out there that gets REALLY loaded. I think that ours is at the top. I have one rule that I believe in. Never use more the half throttle while pulling long steep grades. And DO NOT care how fast I'm going. Bob Dunahugh 78-403 Royale.
________________________________
From: Bob Dunahugh
Sent: Friday, April 26, 2019 2:14 PM
To: gmclist@list.gmcnet.org
Subject: RE: The Olds 403/455 were an outstanding choice for our GMC's
The hardest things on any engine are. Lost's of cold starts, short trips, and luging with too much throttle. Our GMC's have few cold starts as to miles driven. Not much for short trips. And get a 3:70 final drive. With standard 10W-30 oil/filter changes in the range of 3000 miles. Plastic timing gear changed out. Howell/GM EFI helps a lot. 200,000 shouldn't be a problem. I have the 403 that came out of our burned 78 GMC. Has never been apart except for the plastic cam gear replacement. Idle oil pressure hot is just under 30 PSI. Compression readings 140 to 145 PSI. ( New 150 to 155 PSI.) Used a qt of oil in 2500 miles. And has 154,000 miles on it. And I'm looking for another GMC to put that 403 in. Our present 78 Royale, 403, gets lots of oil changes. 3:70 FD, and a Howell/GM EFI. Bob Dunahugh
_______________________________________________
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| Re: [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's [message #342945 is a reply to message #342855] |
Mon, 29 April 2019 12:46 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
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Senior Member |
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Being as Dunahugh is the Guru, I'll gently hijack his thread - or Mike's. Anyhow, local guy wants to sell a '67 Corvair Monza and trailer. Standoff repaint with some bubbles. Interior is in good condition and cleaned up. Automatic car. Engine looks shot - ignition components off, fan and shroud and belt off alternator off carbs off, lotsa greasy dirt n stuff. But a new battery. I figure it's worth the trailer it's on, is there any money magic in a run out mechanical basket case? Like a GMC, if you have room, save it for parts?
--johnny
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
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| Re: [GMCnet] The Olds 403/455 were an outstanding choice for our GMC's [message #342948 is a reply to message #342883] |
Mon, 29 April 2019 12:58 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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We also have the Limited Slip Differential option.
We have been supplying them for few years ad have proven to be a great
option.
I have had many people call me and tell me how much they like what it does
for them.
Limited Slip is just what it says, The front wheels cannot be locked up but
allowed to slip a little when turning corners. So there is a built in
slipage
On Sat, Apr 27, 2019 at 9:44 AM Bob Dunahugh via Gmclist <
gmclist@list.gmcnet.org> wrote:
> Matt said it perfectly on the FD. Not a weak part. Just the wrong part. To
> me. Jim K's 3:70 FD is a great ratio. Towing or NOT. The 3:55 to 3:21 do
> help some. I see it that. If your spending the money. Why not get the most
> benefit from that cash outlay. Want to take the most load off your trans.
> And have it run cooler? The 3:70/4:10 will do it. And the power drive does
> nothing beneficial for the trans. That's a fact. It just makes it easier to
> put more load on the trans. After installing the 3:70. Gas mileage went up
> due to running a higher intake vacuum. I'll get off my box now. ( Grin.)
> Want to keep me off my box? Don't talk about drivetrain components. Bob
> Dunahugh 78 Royale
>
> ________________________________
> From: Bob Dunahugh
> Sent: Saturday, April 27, 2019 1:16 AM
> To: gmclist@list.gmcnet.org
> Subject: The Olds 403/455 were an outstanding choice for our GMC's
>
> My 425 trans/3:70 have been in service since 2003. In two different 78
> Royales. I personally rebuilt it in that year. And now have 87,000 miles
> on the pair. We've gone on one trip in all those years without towing
> something. Thus my lowest GVW all that time. Comes in at 17,000 lbs.
> When I'm towing my 24 ft trailer enclosed trailer. That has a shop/Yenko in
> it. My GVW comes in at just under 25,000 lbs. And all this with a 403. I
> don't use any synthetic oil/fluid/lubes. Never let the engine oil/filter go
> more the 3,000 miles. Change trans fluid every year. FD, and power steering
> fluid every other trans fluid change. I strongly believe that changing
> oil/fluids is the key to longevity. Over the use of synthetics. Oils CHEEP.
> Not rebuilds. So if there's a GMC out there that gets REALLY loaded. I
> think that ours is at the top. I have one rule that I believe in. Never
> use more the half throttle while pulling long steep grades. And DO NOT care
> how fast I'm going. Bob Dunahugh 78-403 Royale.
>
> ________________________________
> From: Bob Dunahugh
> Sent: Friday, April 26, 2019 2:14 PM
> To: gmclist@list.gmcnet.org
> Subject: RE: The Olds 403/455 were an outstanding choice for our GMC's
>
> The hardest things on any engine are. Lost's of cold starts, short
> trips, and luging with too much throttle. Our GMC's have few cold starts as
> to miles driven. Not much for short trips. And get a 3:70 final drive.
> With standard 10W-30 oil/filter changes in the range of 3000 miles.
> Plastic timing gear changed out. Howell/GM EFI helps a lot. 200,000
> shouldn't be a problem. I have the 403 that came out of our burned 78 GMC.
> Has never been apart except for the plastic cam gear replacement. Idle oil
> pressure hot is just under 30 PSI. Compression readings 140 to 145 PSI. (
> New 150 to 155 PSI.) Used a qt of oil in 2500 miles. And has 154,000 miles
> on it. And I'm looking for another GMC to put that 403 in. Our present 78
> Royale, 403, gets lots of oil changes. 3:70 FD, and a Howell/GM EFI. Bob
> Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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