1983 454 vs 5.3 LS for towing

[SirRobyn0]

Thanks all, I think it makes sense to ensure the cooling systems is in good shape, I think Ill start there. If it cools off a bit ill do a test run locally with the trailer.

Im also thinking adding a trans temp gauge would be a good idea. Anyone have expenience with the trans coolers that have their own little fan?

Adding a trans temp gauge is more than a good idea, you really should have one if your towing regardless of the transmission. The gold standard for sensor location is the transmission pan. With that said mine is in the test port. It may not be the ideal location (varies depending on the tranny guy you ask if it's acceptable there or not) My feeling is I seem to get readings that make sense based on load, but I don't have to worry about hooking the wiring on something when I'm in a field since it's tucked up high. Transmission cooler, if it doesn't already have one. Again that's not specific to your combination, it's just stuff you should have if your going to tow much at all. IMO

 

[BeefSupreme]

Adding a trans temp gauge is more than a good idea, you really should have one if your towing regardless of the transmission. The gold standard for sensor location is the transmission pan. With that said mine is in the test port. It may not be the ideal location (varies depending on the tranny guy you ask if it's acceptable there or not) My feeling is I seem to get readings that make sense based on load, but I don't have to worry about hooking the wiring on something when I'm in a field since it's tucked up high. Transmission cooler, if it doesn't already have one. Again that's not specific to your combination, it's just stuff you should have if your going to tow much at all. IMO

Yeah I do have a cooler on it, came with the truck. Looks like a standard mini radiator version. I also have an 08 yukon with the 4L60e, so basically a newer 700r4. It has a factory trans temp gauge so I think ill use that for a baseline.

 

[Hunter79764]

I'm a big fan of LS's, but they do have limits. You are probably better off with the 454 unless you just want something different. And if you do, that's your call, no need to justify to us
For some information, this was a pretty good comparison of the various LS engines and a 454, granted it's a later one. If you want the reliability of modern EFI, you want to tow, and you want to do a swap, I think you have 2 good options. One is an 8.1 swap, and the other is boost on whatever engine you like within reason.
If you have a yukon and have towed with it, then you already have a good comparison. I'd think the weight of the yukon and the truck would be comparable?

xc_hide_links_from_guests_guests_error_hide_media

 

[Matt69olds]

If you are towing, go big block all the way. The lamest 454 will have more off idle torque than any stock 5.3 LS.

As for the 700, run it until it gives you trouble. Hopefully the shop that did the build included some durability upgrades. Specifically, an upgraded 3-4 clutch pack, and some hydraulic improvements to get rid of the girlie-man shifts.

Install the biggest/best transmission cooler you can. Heat is the biggest concern.

Which brings me to the next topic: trans temp gauge. If you are working the truck hard, you can never have too much instrumentation. Good rule of thumb is 100* over ambient temp. It won’t necessarily hurt if it occasionally gets warmer than that when you are really working it, but once the abuse is over it should cool down fairly quickly.

Don’t put the temp probe in the line pressure test port. At best, it’s a useless location. If you look at a hydraulic chart, you will see that line pressure is TEEd off the manual valve. There is zero fluid flow past the sensor, you are basically reading the temp of the case. It will be extremely slow to react to temp changes. Get a Dorman drain plug kit and weld it to the pan. It’s already drilled for the 1/8 pipe thread. This will also give you an excellent opportunity to check out any debris on the pan.

As long as the transmission doesn’t “hunt” (meaning constantly downshifting/upshifting) towing in overdrive is perfectly acceptable. If the trans hunts, put it in “D” until the road conditions allow the trans to stay in high gear. The constant shifting creates heat, which is what really damaged the trans.

What are you doing for a lockup converter control? If it’s on a toggle switch, be careful. It’s really easy to slip the converter clutch. The factory lockup controls used vacuum switches and throttle position to control the converter. Most aftermarket or custom installations don’t. When in doubt, unlock the converter.

 

[Bennyt]

I have a similar set-up. '90 CC DRW w/ BB/ 700r4/ D70.

I plan to add a GearVendors as well. Everyone I talk to that has one behind the 700r4 says it drops the temp considerably and really helps the trans last longer as it gives you the additional gears and an OD you can tow in and double OD for when you are empty.

When and if the 700 breaks, I'll probably switch it to a 4l80 or whatever the strongest trans is at the time.

 

[SirRobyn0]

Install the biggest/best transmission cooler you can. Heat is the biggest concern.

Which brings me to the next topic: trans temp gauge. If you are working the truck hard, you can never have too much instrumentation. Good rule of thumb is 100* over ambient temp. It won’t necessarily hurt if it occasionally gets warmer than that when you are really working it, but once the abuse is over it should cool down fairly quickly.

What are you doing for a lockup converter control? If it’s on a toggle switch, be careful. It’s really easy to slip the converter clutch. The factory lockup controls used vacuum switches and throttle position to control the converter. Most aftermarket or custom installations don’t. When in doubt, unlock the converter.

I want to focus in on trans temps for moment.

First it is surprising to me how cool my 700R4 (with large plate and fin type cooler) will run even when it is very hot out as long as I can keep the converter locked up. Climbing some of the passes around here it is sometimes impossible to avoid spikes, but turning higher RPM's and not laying into the converter helps.

 

[82TwoHeadlight]

GM 700R4, 4L60 & 4L60E Transmission Cooling Pan

GM 700R4, 4L60 & 4L60E Transmission Cooling Pan Cooling Pans Transmission Cooling Pan, GM 700R4/4L60/4L60E 14204, 14207, 14208, 14200, 14201, 14202, 14204, 14207, 14208, 14210, 13010, 14000, 14002, 14010, 142xx

derale.com

I use this in conjunction with a fin type cooler in front of the radiator.
This pan is great. It holds more fluid and comes with a port for a temp sending unit. In the peak of summer with a 2400 stall converter, which will run hotter than a stock converter, I don't see Temps above 160. It runs mostly at 140 degrees or less.

 

[Grit dog]

First, is it actually getting hot?
Our 86 with a late 90s stock 454 in it sits at “210” on the dash gauge and a shade higher if hot out and stop n go for a long period of time like a traffic jam or a Mainstreet cruise. Idk what it actually runs nor what thermostat it has because it doesn’t overheat, doesn’t burp any coolant and never even smells “hot.”
454/700r4 vs 5.3/4L80? Idk, could go both ways. And unless you think there’s a good market for your 700, why not just use it? If it’s a good trans, it’ll tow a little trailer a long time. It’s not like those things didn’t tow trailers back in the day. There’s just better options now if you’re going to do serious mods to the truck.
It’s a bird in hand thing imo.

 

[BeefSupreme]

GM 700R4, 4L60 & 4L60E Transmission Cooling Pan

GM 700R4, 4L60 & 4L60E Transmission Cooling Pan Cooling Pans Transmission Cooling Pan, GM 700R4/4L60/4L60E 14204, 14207, 14208, 14200, 14201, 14202, 14204, 14207, 14208, 14210, 13010, 14000, 14002, 14010, 142xx

derale.com

I use this in conjunction with a fin type cooler in front of the radiator.
This pan is great. It holds more fluid and comes with a port for a temp sending unit. In the peak of summer with a 2400 stall converter, which will run hotter than a stock converter, I don't see Temps above 160. It runs mostly at 140 degrees or less.

This is great, expensive, but not at much as a rebuild or swap lol. Seems well worth it, might see if I can fit one on the Yukon as well.

 

[Mogulmasher]

I'd stick with 454. Day to day empty with a 5.3 would be better but wouldn't tow as well. If ya gotta scratch the ls itch a 6.0 would be a better choice for towing.

I've had gmt800 trucks with 5.3, 6.0 and currently an 8.1. The 6.0 does way better than a 5.3 but my current 8.1 outdoes them all. The 8.1 is basically the last iteration of the old big block chevy, they are a great motor to tow with. Cool thing is they will bolt into anything a 454 was in.

 

[papstruck454]

I would say 454 all the way. I have a stock 2009 Silverado with a 5.3 and regular tow a mower trailer with it maybe 3000lbs total up and down Tennessee hills. My 78 k15 with 454 and sm465 4 speed can pick up speed with same trailer by rolling into throttle. On the 5.3 it is all the time downshifting because it has no low end torque. Night and day difference. Basically the 454 makes it look easier than the 5.3

 

[Big Ray]

I'd go with a 4l80 or manual.
454 makes torque at a lower rpm
I have a L29 sitting in my garage...and a NV4500...

 

[JBswth]

About a year ago I bought a 1983 C35 3+3 dually. Its currently a 454 with a 700r4. Fires right up and cruises fine on the highway, I drive it to work regularly.

Here's my issue:

I want to be able to use it to tow a 5-6000 lb trailer about an hour or so on occasion to get my tractor to and from my property. I don't trust the 700r4 to tow at all, even though it was rebuilt by a reputable shop about 2 years ago. Also, with the recent heatwave the engine has been creeping a little above the 210 mark on the temp, and that's with no load.

Im planning to 4L80 swap it to get the dependability in the towing. I have a 5.3 LS I can install at the same time, but would this be an upgrade in towing from the 454? I would imagine the day to day would be better, and certainly lighter. Any thoughts or experience is welcome.

I would stay with the 454. The 5.3 is, I think, about 327 cubes, and to make matters worse, is cammed and ported for revs over low-end torque. I am leery about the 700R4, but others say it has been proven to be a good trans. You should look into your cooling system though and have your radiator rodded out, and if you have a 195 degree thermostat, I would replace it with a 180 degree stat, as 195 is just too hot. It was chosen to ensure that you would have lowest possible Unburned Hydrocarbon readings in smog tests, not for the coolest running. Ideally, you should have the tall wide radiator and the 20 inch cooling fan, as well as a shroud.

James

 

[Bextreme04]

I actually have some experience with both of your use cases.

I have a 2011 Suburban with a 5.3/6l80(lower first gear than a 700R4 plus double overdrives) and we use it to tow our 6500lb travel trailer. The 5.3 is underwhelming to say the least. Even after switching to 4.11 gears it does not like pulling steep hills at all. I have put the biggest cooler I can on it(Tru Cool 40k) and have it run through the radiator as well. I will usually see 40-60 degrees above ambient when unloaded and if I am full throttle, pulling a long grade, in 100 degree plus ambient temps, with the converter unlocked and in 4th gear, it will get up to about 200 degrees. As soon as I top the hill and it shifts into 5th and locks the converter, the temps will drop right down to about 170 again.

Since it is getting up near 230k miles on it, I found a 6.2LS motor locally for a steal an snapped it up. Should be out of the machine shop in the next few weeks and then it will be getting swapped in towards the end of this year. That engine with a TSP L92 VVT cam should be running right around 450hp at the top end and 400ft-lbs of torque from 2k-6k rpm(the VVT really helps keep a nice flat torque curve). I'm hoping the extra HP and Torque will really make it tow MUCH better all the way around.

Now, for the other instance. In my square I originally have a 350/TH400/NP205 and it tows worse than my 2011 suburban. Even with a rebuilt motor with better cam, compression, headers and intake, it can't compare pulling grades. It does just as well on the low end and on flat ground though. I am swapping in a rebuilt L29 454 and 4L80 from a 97 K2500 Suburban. I converted the L29 to CNP, upgraded injectors, adjustable FPR and LS computer and have built the 4L80 with dual feed and some basic upgrades. I should find out by the end of the year which one pulls better. Hopefully I'll have the suburban swapped out in September sometime and we have at least one pull through the mountains for a Thankgiving family get together. The following day after that I will be pulling the same trailer out to the coast for Elk hunting in my square, so I should have back to back comparison.

 

[RecklessWOT]

Thanks all, I think it makes sense to ensure the cooling systems is in good shape, I think Ill start there. If it cools off a bit ill do a test run locally with the trailer.

Im also thinking adding a trans temp gauge would be a good idea. Anyone have expenience with the trans coolers that have their own little fan?

I don't have one with a fan, but my 'burb has a B&M trans cooler and temp gauge (where the clock would go) that mounts in front of the radiator. It's just a 1/2 ton with a 350 and a 700r4, but I have towed MANY heavy trailers through the mountains, never had any overheating problems with the trans OR engine (except that one time my fan clutch blew out while towing, go figure). In the winter I actually have to block off the trans cooler if I ever want it to get over 100*f