Diesel pros and cons

[FastOrange]

I have driven, owned and dealt with enough of them in my lifetime to know that is completely untrue. They also are an un utter failure on all accounts, and hardly have enough power to move their applications without overheating. In GM's infinite wisdom they carried on with these abominations until they finally figured out having the largest cubic inch gas engine in a pickup truck only was silly and implemented the 454 in the 90's. The 427 was a much better suited engine for medium duty and up applications but in stock form was no fun to drive. The 366 has no business being in a 3 ton truck and is a big, gutless fuel slurping pig. I remember a magazine article about a farmer who put a 360 HP LS5 454 into his late 70's 3 ton single axle grain truck. Like all the 366's I know, his got 4 mpg and struggled to do anything. The 454 of course having over double the power moved the truck with ease and his mileage doubled to 8 mpg under the same load conditions. Good job GM. School bus, sure, or 2 tons and down. The only good thing about a 366 is it shares the 3.75" stroke of the 427 and gives you ample supply of the heaviest 3/8" big block rods made and forged cranshafts. Otherwise they are a waste of cast iron.

x2.

366 were junk, scrap metal, only thing good in them is the Crank, Rod and Main Caps (4-Bolt)

 

[454cid]

That doesn't mean they were good for anything. Don't defend something you have zero experience with just because it has the GM brand tacked to it. The Gov Bomb has been around since 1973 and it's still as much of a failure now as it was back then.

It's a matter of opinion. While researching the Dodge version of the AAM axles, I saw a guy wanting to swap a G80 into his Dodge, and a few GM guys saying that they had no problems with theirs. So again, it's not all bad.

 

[88GMCtruck]

well the diesel question fell into play based on the year of the truck. id like to find an obs 6.5 in good shape. but if it was a nbs id probably go with the 6.0

If your going to get a 6.5L, IMO best 2 years are 92-93 and 99-00.

92-93 are DB2 mechanical pumped trucks. Simple. But they suffer from worse cooling so could use a few upgrades in that area.
99-00 trucks have the best of 6.5L production upgrades. 8 quart oil capacity, ceramic roller IP, dual t-stat & high flow water pump, 9 blade clutch fan, 18.5:1 compression, no cat, and misfire detection.

 

[454cid]

If your going to get a 6.5L, IMO best 2 years are 92-93 and 99-00.

92-93 are DB2 mechanical pumped trucks. Simple. But they suffer from worse cooling so could use a few upgrades in that area.
99-00 trucks have the best of 6.5L production upgrades. 8 quart oil capacity, ceramic roller IP, dual t-stat & high flow water pump, 9 blade clutch fan, 18.5:1 compression, no cat, and misfire detection.

I'll have to remember that. I'd kind of like to own a 6.5L. I know they don't have the best reputation, and they're not going to produce the same power as other diesels, but I love the sound they make. I hope with proper care a 6.5L would make a good daily driver. Their heritage is more fuel economy than powerhouse, so that would fit well with my use.

 

[88GMCtruck]

Exactly. I'm getting 15MPG in town and have gotten as much as 26MPG on the highway really babying it. Typical highway seems to be 19-22MPG, which isn't bad for a fullsize truck.

 

[454cid]

Exactly. I'm getting 15MPG in town and have gotten as much as 26MPG on the highway really babying it. Typical highway seems to be 19-22MPG, which isn't bad for a fullsize truck.

What do you have for gears?

 

[ndians68]

well from everything ive seen those 366 are pretty good motors, they are still in tons of dump trucks around here and the one that is now in my cousins rat rod was in a bus used for boy scout trops going on trip and goin different places through the city it was in. idk where you get they were junk, my uncle still has a dump truck with a 366 and the funny thing is the motor is outlasting the rest of the truck. so maybe you guys all just got a bunch of crappy ones...

 

[Badass69]

well from everything ive seen those 366 are pretty good motors, they are still in tons of dump trucks around here and the one that is now in my cousins rat rod was in a bus used for boy scout trops going on trip and goin different places through the city it was in. idk where you get they were junk, my uncle still has a dump truck with a 366 and the funny thing is the motor is outlasting the rest of the truck. so maybe you guys all just got a bunch of crappy ones...

Just like the people that love the Gov Lock, you will find supporters for anything. Underpowered, terrible on fuel and utterly useless with a load on, what a winner. They are no stronger, better built or better suited than a 350 in the same truck. In fact the 350 is probably a step ahead considering the engine weighs less. Fine for a school bus that never hauls anything with any weight, but I wouldn't want to pay for the fuel it eats.... hence why they mostly seem to go to propane. They are all junk in the sense of what they built to do, like it or not.

But hey if you like them, kudos to you.

 

[88GMCtruck]

What do you have for gears?

Truck has a NV4500 / 3.73s / 235/85R16s

 

[454cid]

.......They are no stronger, better built or better suited than a 350 in the same truck......

Tall deck with extra rings in the 366 and thicker cylinder walls. I've seen a 350 in a medium duty, but am under the impression that those are swaps.