1988 GMC 3500K Sierra advice

[sologal70]

I have owned a 1988 GMC 3500K Sierra for many years. I want to buy a travel trailer and am wondering what limitations I should be concerned about. My thought is to "practice" hauling in my home state (Iowa) to shake down my future used travel trailer and before going on the road. I don't think I would want to use this old of a truck to do long distance trips. It has about 135,000 miles on it. Or maybe I'm being paranoid as I guess a new truck can have problems too. I guess I'm thinking as I practice camping more locally I will eventually run across a sale of a newer (diesel?) truck. Then I can tackle doing longer term trips.

I have a brake controller installed as I used it for my gooseneck horse trailer. It has a pretty heavy duty towing hitch (big springs). I had a friend pull a 30' sailboat from western Nebraska to Eastern Iowa one year.

According to the web, my wheelbase is 141.5" (club cab with full bed) which sounds like it can pull up to a 27' travel trailer. Does that sound correct? It is a 5.7 L V8 which according to charts is 185 hp (138kW) @ 4000 rpm 295 lb.ft (400 N.m) @ 2400 rpm. The GVWR is over 8500 lb. Is there other specs I need to know?
Kim in Iowa.

[blofgren]

sologal70 wrote:
Wow! Thanks so much for the feedback! You guys rock!

Good news for me. I found a new to me pickup, so the worries of using my old one is in the past.

My new pickup is a 2008 Dodge Ram 3500 Cummins 6.7L quad cab long bed. It has 71,400 miles on it. I had it checked over carefully by a reputable Diesel shop. So I am good to go! Next is to get a camper. You may see me post in other threads in this forum.

My old pickup will be going up for sale this Spring, along with a gooseneck horse trailer, so I am sure it will sell quickly, as those are in demand here in Iowa. The truck was garaged every winter and there is no rust, so it is in great condition for its age. I will miss it though, it has a lot of memories.

Great thread; I remember vividly when the 1988 trucks came out, right close to the time of the 1988 Calgary Winter Olympics. They were certainly state of the art then and were much sought after. I also remember when the glued on doors started falling off......

In any case OP you are going to be a very happy camper when you tow with your new truck and even happier when you see the fuel economy. Please report back and let us know! :B

[Camper_G]

op, congrats! now your set!

but since we're reminiscing....

back in the day I had a 1989 Chevy k1500 4x4, standard cab, 8' bed.

it had the tbi 350, 4 speed auto, not sure what rear. I installed one ton springs in the rear which really helped with rear end sag. it was direct bolt in.

I pulled a 1987 wilderness Yukon 25C, which was the basement model, over 26' long and 6700 gvwr.

the old chevy pulled it ok, but there's a long grade going to locust lake state park, coming out of st. Claire on rt 61.

I'd pull that nearly wide open the whole way up, 4,000 plus rpm, which sounded great with the flowmaster I had on it.

however, by the time I got to the top she was hot, 230 degrees, but she did pull strong. back in those days we pulled heavy trailers with much less capable trucks and they got the job done.

I pulled that trailer all over pa with that truck.

I miss it to this day. agree with Marty, that body style Chevy is and will always be one of my favorites. I miss that truck. the sheet metal was so much thicker back then.

I remeber how neat i thought the computerized display for the hvac controls was. I still do, but my how times have changed.... good memories of my early camping days guys......

[Ralph_Cramden]

This thread is a great read. Other than the 30 years old fact, what do people think everyone was towing stuff around with in the 80's? If memory serves me correctly people still towed RV's and many more things much heavier than an RV back then. Of course one thing you did not have was the net and RV forums to muddy up everything with truck loads of BS lol.

[burningman]

I used my old ‘86 GMC K3500 duality 4x4 crewcab to carry a 4000 pound camper while towing a 10,000 pound trailer up and down mountains all over the west coast.
It wasn’t fast, because I didn’t care. I could have swapped in a 12-valve Cummins and ran with the late models, and I almost did just that. I could have hot-rodded the gas motor. I did actually drop in a ‘98 Vortec 7.4. But I wasn’t in that much of a hurry., I didn’t want to break anything.
I still own it. It ALWAYS runs. If it does break, it’s cheap and easy to fix.
No electronics. No emissions. No “trouble codes”.
If a rod isn’t poking out the side of the block, it’s gonna get you home.
New trucks are nice, but ridiculously expensive and FULL of things that can and eventually will go wrong.

[jrp26789]

So, let me be the bearer of good news. I owned a R3500 with the 454. Also several 350 trucks in that era. What’s being missed here, with a little mechanical knowledge and a few bucks that truck will be a decent tow vehicle. Intake and carb, strip the injection, headers and true duals with a cross over will yield nice results. Change the cam and heads and that 350 will easily be over 300 hp. But it really depends on condition, ability and desire. My R3500 sucked in stock form. Exhaust manifolds were glowing red at the top of 5% grades and it got 3 to 4 mpg towing 8000. I figured in fuel savings alone I could afford a newer truck.

[sologal70]

Wow! Thanks so much for the feedback! You guys rock!

Good news for me. I found a new to me pickup, so the worries of using my old one is in the past.

My new pickup is a 2008 Dodge Ram 3500 Cummins 6.7L quad cab long bed. It has 71,400 miles on it. I had it checked over carefully by a reputable Diesel shop. So I am good to go! Next is to get a camper. You may see me post in other threads in this forum.

My old pickup will be going up for sale this Spring, along with a gooseneck horse trailer, so I am sure it will sell quickly, as those are in demand here in Iowa. The truck was garaged every winter and there is no rust, so it is in great condition for its age. I will miss it though, it has a lot of memories.

[Thunderbolt]

Down low I think my TBI 350 pulled as good as my vortec, but once you hit about 30 mph the Vortec felt a lot stronger. Having a Tbi in a 3500 would make it pretty doggy unless it had at least 4:10's. The OP's truck will struggle over 6,000 IMHO. He is the only one that can decide what he is comfortable with. Everyone is different. I work with a guy that had a 2500 with the 350 TBI and he had a few grades in Minnesota where he had to use 4 lo to make it up with his horse trailer.

blt2ski wrote:
Tbolt,
Now that I.think about it, the 88R/V chassis also had tho except for the.C7P 10500 giver C7P chassis set up like my 89. While.the.same hp torque specs, the.power.curve was.enough.different that the 88 K3500 felt more.powerfully than the 89 R3500.
I also do not remember that axle.differences enough on smaller rigs. Other than what I recall from earlier postings. I could not get a locker with a BB in my 88 due.to using a dana70 vs the ff c14 in later models like my 96 k3500.

The tbi and carb versions of.the.4.3, 350 and 454 were way.under powered vs the.vortex.models. Had a 2000 4.3 safari van that felt every.bit as.strong as pre vortec 350s. My.vortex 350 is stronger than 454s mentioned.

Marty

[blt2ski]

Tbolt,
Now that I.think about it, the 88R/V chassis also had tho except for the.C7P 10500 giver C7P chassis set up like my 89. While.the.same hp torque specs, the.power.curve was.enough.different that the 88 K3500 felt more.powerfully than the 89 R3500.
I also do not remember that axle.differences enough on smaller rigs. Other than what I recall from earlier postings. I could not get a locker with a BB in my 88 due.to using a dana70 vs the ff c14 in later models like my 96 k3500.

The tbi and carb versions of.the.4.3, 350 and 454 were way.under powered vs the.vortex.models. Had a 2000 4.3 safari van that felt every.bit as.strong as pre vortec 350s. My.vortex 350 is stronger than 454s mentioned.

Marty

[Thunderbolt]

Actually the 1500's gad a GVWR of 6,200 and came with the 10 bolt rear differential. If you got the F44 heavy duty chassis package you got the 6,600 lb GVWR along with a 14 bolt 6 lug semi floater and an extra leaf spring.

blt2ski wrote:
For those that do not remember. In 88 this was the first year for that body style. ALL 3500's were 8600 gvwr setups, ALL 2500's were a 7200 gvwr, and 1500's a 6600 gvwr. THERE WAS NOT a dually in this body style until 90 or 91. The 2500HD came out in 89 or 90 which only had a tbi 350, along with the 8 lug 8600 gvwr. The SW 3500 now had a 9200 gvwr. Then the dually came out it had a typical 10K gvwr with a 7500 grawr.

Then if the OP is correct with WB, a 141 is a 6' bed, if he had an 8' bed as my 88 had, it would be a 155" WB. A BB in 88 had a dana 70, the 350 the Corp 14 bolt rear axel.

Anyway, max gcwr with this rig is 13500, unless he has 4.56 gears, which would put him at 15K. 3.73's would be 12500, and 3.42s 11500. Heaven for bid he has 3.08's, that would be 10500! The chassis will handle a larger trailer, but as noted, with a whopping 185hp, and not even 300 lbs ft of torque, he will be hurting in the power category from a speed standpoint. My 96 Crew cab with a 185/385 6.5 TD and a NV4500 did pretty good with a 6500 lb trailer, total gcw around 15K. but I was down to 35-40 on 3-5% grades in 3rd, ie gear below direct. That was a better towing tranny than the th400 or 4l80E auto setups, no matter the RA in it. 4.10s like I had were the cats meow from a gearing split stand point. If you had the munci 4sp, and 3.42's, your overall low, and high gear ratio were on par with the 4.10 nv4500. Pretty much from a performance stand point, equal.

marty

[Thunderbolt]

It will be a TBI. They started putting them on the trucks in 1987.

blt2ski wrote:

cpres wrote:
88 c3500 big block powered dually owner chiming in, you know the condition of the truck and how it has towed other stuff. Yhe bottom line is it comfortable for you, I know these older trucks sure slow down uphill compared to new diesel-powered rigs, I travel and enjoy my old truck and no big payment.

"IF" your 88 is a dually, and 2wd, you have an "R3500" IIRC, A V3500 is the 4wd version. Altho it might be the other way around. Been a long time since 1988. I would also swag you have a 4bbl 454.....altho a bell is ringing it may be a tbi. Which my 88 round body would go thru tbi spacer gaskets every 40-50K or so. Made it from almost gutless, to gutless! My 2000 vortec 350 has more umph than the 88 tbi or 4bbl 454 in an 89 square body flatbed.

The only dually in 88-92 or so, was the 80's square body, not the 88 intro of the 90's more rounded body style GM. Which in "MY" eye, the best looking GM since I started buying them in 81. I am positive some like current body styles.....to each his own.

Marty

[blt2ski]

cpres wrote:
88 c3500 big block powered dually owner chiming in, you know the condition of the truck and how it has towed other stuff. Yhe bottom line is it comfortable for you, I know these older trucks sure slow down uphill compared to new diesel-powered rigs, I travel and enjoy my old truck and no big payment.

"IF" your 88 is a dually, and 2wd, you have an "R3500" IIRC, A V3500 is the 4wd version. Altho it might be the other way around. Been a long time since 1988. I would also swag you have a 4bbl 454.....altho a bell is ringing it may be a tbi. Which my 88 round body would go thru tbi spacer gaskets every 40-50K or so. Made it from almost gutless, to gutless! My 2000 vortec 350 has more umph than the 88 tbi or 4bbl 454 in an 89 square body flatbed.

The only dually in 88-92 or so, was the 80's square body, not the 88 intro of the 90's more rounded body style GM. Which in "MY" eye, the best looking GM since I started buying them in 81. I am positive some like current body styles.....to each his own.

Marty

[cathrynh]

I'm confused. My dad has a 1988 GMC Sierra 3500 dually, but it's not a square body, it's the rounded 90s style. But you say those don't exist... am I missing something?

[Grit_dog]

You’re responding to an 8 year old dead discussion, and for why?  To argue with someone about a 30 year old model truck?

Rofl. Run along….pitter patter!

[cathrynh]

Try following your own advice. I wasn't arguing, in case you are bad at context clues. I am trying to learn about my dad's truck.