1998 1/2 ton vs. 3/4 ton both with 350cid

[Hemling]

What is the difference (besides the obvious engine) between these two rigs? Assuming the same suspension, transmissions and gear ratios, are they rated the same or does the big block account for a lot of the towing capacity? The reason is ask is that I cannot find a decent 3/4 ton 454/4L80/4.10 suburban that isn't already trashed. I have a line on a really nice 350 3/4 ton sub., (don't know the year ratio). I have a vortec 350 in another truck, and don't doubt its ability to pull a decent weight, and maybe with a 4L80 and decent gears it could manage 8,000-8,500 in a 3/4 ton chassis?

[rjstractor]

FishOnOne wrote:
Your correct that truck like most 80's and 90's 3/4 GM trucks had a semi floating axle. The 1 ton SRW and DRW had the full floating axle and a different differential to boot.

Yep, my '84 had the semi floating axle with a 7200 GVWR and 8 lug wheels. Decent payload but the 305 carbureted V8 was a gutless turd. My old Ford Explorer pulled the same load faster.

[FishOnOne]

Cummins12V98 wrote:

FishOnOne wrote:

Hideout17 wrote:
Usually bigger brakes, heavier springs, full floating rear axle possibly a few other minor details....

Those Chevy 3/4 trucks didn't have a full floating axle. Also add in heavier frame.

My 86 C20 was a "SEMI" Floater, not sure what to call it. Original one with over 400K.

Your correct that truck like most 80's and 90's 3/4 GM trucks had a semi floating axle. The 1 ton SRW and DRW had the full floating axle and a different differential to boot.

[likestrucks]

I have a 98 K1500 with the 5.7 and 3.73 gears in a 14 bolt semi floater rear end. I tow a 6900 scaled weight tt with it and I never have an issue. Total combined weight is about 12500. The same engine in the 2500 will feel less powerful because the 4L80E although beefier is less efficient at putting the power to the wheels. The heaviest trailer I have towed with it is 7500 pounds. While I cant speak for heavier, the truck handled these weights like a champ and did not feel down on power considering what it was moving.

[BenK]

Read this thread, which is the same topic...

Other than power, what is 2500 advantage over 1500?

BenK wrote:
IMHO...all the details in the world won't help those who have no knowledge of how
this stuff works...repeat...it is like trying to explain sex to a virgin...they
have no basis or knowledge (ignorant, not a slight...that is the correct word...look
that word up)

Maybe this might get that message across

To these folks with no knowledge or experience of what this topic/thread is about,
maybe these visuals of sledge hammer heads might get that across

This is also a very, very, very common thread on half tons (AKA lowest
class full sized TV) for both newbies and advisors. Not just here, but
in most all forums I visit. Boy racer forms do understand and know because
they push it and break stuff much more often than here...

Sledge hammers come in various 'ratings', or 'weights', or 'class'. I have a 2 lb,
8 lb, 10 lb and a 16 lb sledge hammers. All but the 2 pounder looks the same, has
about the same head size, etc...just like the OP seeing the 1500/half ton Sub
looking exactly like the 2500-3/4 ton Sub...they both have the same body...except
for the badging

The higher class Sub (2500, or 3/4 ton, or 8.6K GVWR) has a bigger/heavier:

• Frame
• Suspension
• Tranny
• Diff
• Wheels
• Tires
• Drive shaft
• U-Joints
• Brakes
• etc, etc, etc, etc

All stuff not readily seen, nor measured...nor understood their differences
in this matter

Even the software is different...and...get this...many times some of
those attributes are 'de-tuned' for the higher class...even though the
part is the same between the lower class and higher class
















This is all part of the ability to 'manhandle' the setup/situation. Not
a 'can do', but to do it well and for a long time. Like folks thinking
the TV that towed the Space Shuttle is of a higher class...but what
they miss is that the Shuttle was in it's 'DRY' weight condition, that
it was just a few miles and Mr Murphy did not cross it's path so that
it would have needed all of the rating margin it could muster or had
left...or how long could that TV tow that Shuttle...shown in that
video for maybe a few miles...anyone think it could for 100,000 miles? :R

[BluegrassBill]

The weak point of a 1/2 ton is the brakes and drive line,U-joints and rear-end gears and yoke. Get the 3/4 ton.

[blt2ski]

my 81 was a SF also

marty

[boogie_4wheel]

blt2ski wrote:
My 2000 GM C2500 is a semi floater. Granted a C14 10.5" R&P. The BB got a full floater. I have 8 lugs, 10 ply tires, 8600 gvwr etc etc.

marty

Never seen one... Learn something new every day. I thought all got the FF and only the LD2500 (or heavy half, the 6-lug was still the SF axle). I never have seen an 8 lug SF.

Thank you.

[blt2ski]

My 2000 GM C2500 is a semi floater. Granted a C14 10.5" R&P. The BB got a full floater. I have 8 lugs, 10 ply tires, 8600 gvwr etc etc.

marty

[boogie_4wheel]

FishOnOne wrote:

Hideout17 wrote:
Usually bigger brakes, heavier springs, full floating rear axle possibly a few other minor details....

Those Chevy 3/4 trucks didn't have a full floating axle. Also add in heavier frame.

You must be thinking of the LD2500 6-lug... They had the 14B SF axle (I had a '97 K15 with the Semi Floater 14). But a true 8-lug 2500 series does have the full floater.


I would wait for the big block. I drove a late 90's 1-ton (crew/dually) with the 350 and it flat out sucked, and I ran a '97 K1500 to 244k before I sold it. Sorry, the L31 350 just doesn't have the torque. If you could find one that was 4.10 gears AND was a 5spd manual AND was an absolute cream puff, then I might go for it. The extra gear and ability to hold a gear will help a bunch.

I pulled my sig trailer (6000lbs empty) with my K15 350/60E/3.73 and it was less than satisfying. I was right at my 12k GCWR. I was continually watching my throttle application in an effort to keep the torque convertor locked in 3rd in an effort to keep the transmission temperature at an acceptable level. The 80E wont make a difference here. I actually added a lock-up switch to force the TC to lock just to control transmission temps, and that was with the factory aux cooler plus a cooler that I added. The engine still had a little power available, but trans tuning and capacity was sub-par.

A 5spd stick running in 3rd and 4th, and a Blackbear tune on the engine, and it could work, as long as you don't try to go cross country with it.

[Cummins12V98]

FishOnOne wrote:

Hideout17 wrote:
Usually bigger brakes, heavier springs, full floating rear axle possibly a few other minor details....

Those Chevy 3/4 trucks didn't have a full floating axle. Also add in heavier frame.

My 86 C20 was a "SEMI" Floater, not sure what to call it. Original one with over 400K.

[blt2ski]

I have a 2000 C2500 with a vortec 350, 4.10 rear end, and the 4l80E trans. I've pulled upwards of 12K with mine. Te 12K day I was quite surprised at how well it did. OTHER THAN it did not have a WD, which would have helped from a how much wt was pulled off the FE. other than that, really no issues. I have pulled in the 6-8k range. It does every bit as well as the 4bbl/TBI 454's I have had, probably better with equal total loads. IMHO, the rating is a bit on the low side. The vortec is 255hp / 335 ft lbs of torque IIRC.
The BIG issue in my mind and past history, IS the blanky blank blank 4L80E trans. Behind the BB's I got if lucky 40K out of it. The 200 has 94K and still has the original 4l80e in it. Not sure it frankly is up to the task of BB torque, and still surviving. Then again, it has the tallest 1st gear ratio at 2.48 vs the dodge and ford 4 sp offerings at 2.7-2.9, and the GM 4l60e at 3.08. I barely like the low end on a 4.10 geared rig, would not want a taller RA of any sort! 4.33 or 4.56 would be better, but with out a DOD, that makes too many R's are 60-70 mph.

marty

marty

[jerem0621]

Just pay attention to the axle ratio... The 350 with the 3.73 gears in the 2500 is only rated at 6,000 lbs. the 4:10 get 7,500 worth of trailer weight rating.

IMHO... Wait for the 454...expand your search area and be ready to travel to find that gem... It's out there...and a few months waiting for the right truck more than offsets months to years of wondering if you should have bought the 454.

Thanks!

Jeremiah

[FishOnOne]

Hideout17 wrote:
Usually bigger brakes, heavier springs, full floating rear axle possibly a few other minor details....

Those Chevy 3/4 trucks didn't have a full floating axle. Also add in heavier frame.

[DanNJanice]

Hemling wrote:
What is the difference (besides the obvious engine) between these two rigs? Assuming the same suspension, transmissions and gear ratios, are they rated the same or does the big block account for a lot of the towing capacity? The reason is ask is that I cannot find a decent 3/4 ton 454/4L80/4.10 suburban that isn't already trashed. I have a line on a really nice 350 3/4 ton sub., (don't know the year ratio). I have a vortec 350 in another truck, and don't doubt its ability to pull a decent weight, and maybe with a 4L80 and decent gears it could manage 8,000-8,500 in a 3/4 ton chassis?

The main difference is that the 3/4 ton will usually have a higher payload, somewhere around 2500lbs, while the 1/2 ton will have payload around 1500lbs.
Anything of that vintage will be pretty "long in the tooth". I would probably try for something in the 2002-2005 range. If you are lucky you might actually find something with less than 100000 miles.