72 Blazer tow rig

[Boondocks]

I am planning to upgrade my camping trailer to something substantially larger than my current 18 footer. Most likely 28 to 32 feet and around 9000 pounds.

So, the question is, should I upgrade the drivetrain in my 72 Blazer? The engine is already plenty powerful with the GMPP 383HT, but I worry about the TH350 and the stock axles.

I already have a class IV hitch and am wired for brakes, etc.

I don't wheel that hard, but there are some substantial grades on the way to hunting and in it is mostly uphill all the way there.

At a minimum I would think I need better brakes, even with trailer brakes.

My goal is make the Blazer safe and capable for this application.

Your recommendations are appreciated.

 

[88sub4x4]

How often and how far do you plan to tow? I will probably hear it for saying this, but 9K is a little too heavy for a Blazer. Usually around 6K is the limit. I definitly would upgrade the rear axle to a 14BFF at a minimum. Rear disks, or at least 13" drums too. A class 4 or 5 hitch with a good weight distributing setup is also a must. You said you are already wired for electric brakes so you're good in that dept. The TH350 will do it but it won't be too happy about it. Invest in the biggest trans. cooler you can and install a gauge to watch it's temps. Keep them below 210 and you should be OK.

 

[Boondocks]

I felt that 9k was the very upper limit. I am hoping to find a trailer that is lighter when loaded, and may now make that a requirement.

I realize that even with heavier-duty running gear that the Blazer is still lighter than a heavy-duty truck. But I would like to build it to the highest safe towing capacity I can.

I am willing to install a D60 front/rear and 1 ton booster and master cylinder, if that is what it will take to get me over 7k. I have even considered 4L80 trans, if for nothing else, the four speed. I think my NP205 is strong enough as is.

Also, typical towing use is for hunting once a year. Ocassionally, there are additional camping trips. But, we go from about 2500 feet to 6500 feet and about 150 miles. Of course, there is then coming back down.

 

[88sub4x4]

The running gear is one consideration, but I think the limiting factor on most of the older vehicles is chassis strength. If you look at most of the late model trucks that are rated to tow 12-17K lbs, they have hydroformed chassis and much higher grade steel. Up untill recently even the one ton's were only rated to 10K, and they have thicker chassis with more bracing then your '72. I'm not saying that you will rip your chassis apart, but I would take it real easy when towing that heavy of a load, and all those upgrades you mention are pretty much nessesary to be as safe as possible. On a side note, I have also looked at alot of campers in the past few weeks. Alot of the newer model 28-30 footers weigh in at around 5-6K empty, and 7-7500K loaded, so if your budget allowed that may be the way to go. I know my older ('96) prowler 23' weighs 5K loaded. Also, a 30 ft. trailer is real long for a short wheelbase rig. I used to tow both my 23' and my old 18' with both a bronco and a ramcharger and when I finally started towing with a suburban and a long wheelbase pickup, it became a pleasure to drive. The wheelbase made a huge difference in handling, especially when being passed by semi's. I'm not trying to discourage you from getting a bigger camper, I just want to make sure you do it safely. If it were me I'd stick with a 23-26 ft. camper weighing under 6500 and go with the one ton running gear and brakes, as well at the trans. cooler.

 

[Boondocks]

Good info!

My goal is to stay at or below 28 ft. But we really would like a slider for the living room area and of course, that weighs more.

Good thing is that we are not in a rush, so there is time to both shop for the trailer and modify the Blazer.

I have a trans-cooler now, but was already thinking of upgrading to a better one with a fan. Of course, the trans temp gauge is now a must and is on my list of mods. Thanks for that tip and all of the other info.

I agree that the instability of the short wheelbase will be the limiting factor. Even if I boxed the frame that would still be an issue.

 

[88sub4x4]

The slide for the living room area is exactly why I'm looking at newer ones too.