I recently picked up a 1984 medium duty GMC 70 Topkick/Kodiak truck, with a GM 366 gas engine and 5spd manual trans with 2-spd rear end. I need to change the oil in the truck, but I have had a little difficulty finding the recommended oil and actual capacity. Any suggestions?
Which oil for '84 GM 366?
- Thread starter Jason280
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Rotella T6 5W-40 is where I'd start.
JHZR2
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Any decent 10w-30 or 15w-40 should be fine. Something like rotella or delo 10w-30 is what I'd look for.
Looks like it should be 8 quarts or maybe 9, and there are 1 and 2 quart filter options...
https://www.google.com/search?q=1984+gmc...p;client=safari
Why not drain the oil and measure how much you get out, then account for the filter, and see from there...
Looks like it should be 8 quarts or maybe 9, and there are 1 and 2 quart filter options...
https://www.google.com/search?q=1984+gmc...p;client=safari
Why not drain the oil and measure how much you get out, then account for the filter, and see from there...
If it was mine it'd get Valvoline or Rotella 10 or 15w40 (maybe a stout 10w30 if doesn't get worked hard and seems pretty healthy and tight) with a 2 qt. filter if that isn't already the stock number.
Originally Posted By: Alex_V
If it was mine it'd get Valvoline or Rotella 10 or 15w40 (maybe a stout 10w30 if doesn't get worked hard and seems pretty healthy and tight) with a 2 qt. filter if that isn't already the stock number.
Its getting worked pretty hard, I used it three days last week running over 100 miles round trip at a gross weight of 25,400-27,100 lbs. I need to look into the 2-quart oil filter, looks like it may be a better option.
If it was mine it'd get Valvoline or Rotella 10 or 15w40 (maybe a stout 10w30 if doesn't get worked hard and seems pretty healthy and tight) with a 2 qt. filter if that isn't already the stock number.
Its getting worked pretty hard, I used it three days last week running over 100 miles round trip at a gross weight of 25,400-27,100 lbs. I need to look into the 2-quart oil filter, looks like it may be a better option.
About 5 MPG or so? Done anything to it, or stock?
Two-quart filter (PH373 for Fram) was the old-school way of doing things. You can get a Fram Ultra XG5 for less money (around $8) at your local Walmart; IIRC, DoubleWasp uses these on marine 454's without issue. While you're there getting the filter, Delvac or Rotella 15w-40 can be had in the 2.5 gallon jug for around $30.
Two-quart filter (PH373 for Fram) was the old-school way of doing things. You can get a Fram Ultra XG5 for less money (around $8) at your local Walmart; IIRC, DoubleWasp uses these on marine 454's without issue. While you're there getting the filter, Delvac or Rotella 15w-40 can be had in the 2.5 gallon jug for around $30.
Quote:
About 5 MPG or so? Done anything to it, or stock?
Its stock. Round trip each time was around 110-115 miles, and I burned around 24 gallons each trip. Half of each trip was loaded to 26-27k lbs, the other half was cruising at 11,400lbs.
About 5 MPG or so? Done anything to it, or stock?
Its stock. Round trip each time was around 110-115 miles, and I burned around 24 gallons each trip. Half of each trip was loaded to 26-27k lbs, the other half was cruising at 11,400lbs.
Shell Rotella T6 5W-40 or T4 15W-40 would be my pick.
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Why not the Delo or the Delvac that you use ? - they both have a lower NOACK than T6 and are pillars of HDEO ...
Originally Posted By: Jason280
Quote:
About 5 MPG or so? Done anything to it, or stock?
Its stock. Round trip each time was around 110-115 miles, and I burned around 24 gallons each trip. Half of each trip was loaded to 26-27k lbs, the other half was cruising at 11,400lbs.
4.7 MPG. Love it. I'm looking for an International Loadstar up here, betting on similar mileage...
Quote:
About 5 MPG or so? Done anything to it, or stock?
Its stock. Round trip each time was around 110-115 miles, and I burned around 24 gallons each trip. Half of each trip was loaded to 26-27k lbs, the other half was cruising at 11,400lbs.
4.7 MPG. Love it. I'm looking for an International Loadstar up here, betting on similar mileage...
I love the old gas big block 366/427 GM engines. We had a 427 in a similar truck on our farm with a 7.5 yard dump box on it. I would run a 15w40 SuperTech/Delo/Delvac/Rotella. Our 427 got Farmers CoOp 15w40 or SAE 40 as long as we owned it.
If you can find it, O'Reilly's was discontinuing the Delo 15W30 SD HDEO for around $8/jug, that would be perfect for that engine.
Originally Posted By: Matt6127
Originally Posted By: Jason280
Quote:
About 5 MPG or so? Done anything to it, or stock?
Its stock. Round trip each time was around 110-115 miles, and I burned around 24 gallons each trip. Half of each trip was loaded to 26-27k lbs, the other half was cruising at 11,400lbs.
4.7 MPG. Love it. I'm looking for an International Loadstar up here, betting on similar mileage...
had a international 392 in a 3/4 ton pickup. 6mpg on a downhill. Usually got 4.5-5 mpg.
Originally Posted By: Jason280
Quote:
About 5 MPG or so? Done anything to it, or stock?
Its stock. Round trip each time was around 110-115 miles, and I burned around 24 gallons each trip. Half of each trip was loaded to 26-27k lbs, the other half was cruising at 11,400lbs.
4.7 MPG. Love it. I'm looking for an International Loadstar up here, betting on similar mileage...
had a international 392 in a 3/4 ton pickup. 6mpg on a downhill. Usually got 4.5-5 mpg.
I've been told I might get a little better mileage with a tune up, but I am not real familiar with carb'd truck engines. I may check the plugs and timing, but first order is to get the oil changed. I'm debating on changing the rear end and transmission fluid as well, certainly wouldn't hurt....I just have to find out exactly what they are, so I can figure out which fluid to use.
I've been very impressed with how well the truck has run so far. Won't win any races, but cranks easily and pulls hard. This is my first experience with the GM 366, and its made a believer out of me!
I've been very impressed with how well the truck has run so far. Won't win any races, but cranks easily and pulls hard. This is my first experience with the GM 366, and its made a believer out of me!
For a filter, look no further than the Fram XG5. There is a much larger filter option available, but it is a complete rock catcher. The XG5 will filter much better.
For engine oil, I would just use Delo in 15w40. It's a dirt cheap oil that puts a lot of high dollar synthetic HDEOs to shame.
The larger 454 big blocks cannot beat up 8 quarts of that oil being run at 4000rpm all day long in marine applications over a 150 hour OCI. Your smaller 366 big block will not in your use. So don't worry about sump capacity or a huge filter.
To sum it up:
Fram XG5
Chevron Delo 15w40
Harsher Environment
+ Bigger Engine
Can't Touch This
Run the heck out of it, and don't worry.
For engine oil, I would just use Delo in 15w40. It's a dirt cheap oil that puts a lot of high dollar synthetic HDEOs to shame.
The larger 454 big blocks cannot beat up 8 quarts of that oil being run at 4000rpm all day long in marine applications over a 150 hour OCI. Your smaller 366 big block will not in your use. So don't worry about sump capacity or a huge filter.
To sum it up:
Fram XG5
Chevron Delo 15w40
Harsher Environment
+ Bigger Engine
Can't Touch This
Run the heck out of it, and don't worry.
Originally Posted By: bullwinkle
If you can find it, O'Reilly's was discontinuing the Delo 15W30 SD HDEO for around $8/jug, that would be perfect for that engine.
Down to 3.07 a gallon, and I have most of the Midwest stock in my garage.
Second the Delo 15w40 recommendation.
If you can find it, O'Reilly's was discontinuing the Delo 15W30 SD HDEO for around $8/jug, that would be perfect for that engine.
Down to 3.07 a gallon, and I have most of the Midwest stock in my garage.
Second the Delo 15w40 recommendation.
Originally Posted By: Jason280
I recently picked up a 1984 medium duty GMC 70 Topkick/Kodiak truck, with a GM 366 gas engine and 5spd manual trans with 2-spd rear end. I need to change the oil in the truck, but I have had a little difficulty finding the recommended oil and actual capacity. Any suggestions?
Hi @Jason280 - Shell Rotella T6 Multi-Vehicle offers enhanced fuel economy, saving you thousands per year in fuel consumption. Also, depending on where you are from, Rotella T6 resists breakdown by heat and exhibits excellent cold temperature flow. Hope this helps! - The Shell Rotella Team
I recently picked up a 1984 medium duty GMC 70 Topkick/Kodiak truck, with a GM 366 gas engine and 5spd manual trans with 2-spd rear end. I need to change the oil in the truck, but I have had a little difficulty finding the recommended oil and actual capacity. Any suggestions?
Hi @Jason280 - Shell Rotella T6 Multi-Vehicle offers enhanced fuel economy, saving you thousands per year in fuel consumption. Also, depending on where you are from, Rotella T6 resists breakdown by heat and exhibits excellent cold temperature flow. Hope this helps! - The Shell Rotella Team
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