I'm the one who towed my '71 GMC Sprint (5000 lbs with trailer) behind my '68 El Camino - 2700 miles round trip to Chevellabration in Nashville.
That was the first time I had ever driven with a trailer of ANY kind. It was a bit of a "white-knuckle" drive at first, but I got used to it. I never had any close calls or serious trouble. There were a few times that the rig swayed back-and-forth a bit. That was on the interstate where "ruts" had been worn in the lanes. Otherwise, it was fairly stable. The trailer & hitch geometry did cause a significant amount of tounge weight, which caused the rear end to droop. But it never bottomed out. I got stuck in shop-and-go traffic on a hot day on the interstate near downtown Kansas City. The engine & transmission temperatures climbed to nearly 220. I was about to pull over and shut it off when the traffic opened up an it cooled down when I got moving continuously again.
There would be a difference between towing with a '65 vs. a '70. The BIG difference is that the '70 has a longer wheelbase, which helps. El Caminos have a fully-boxed frame which is quite strong and has the capability to tow a lot. It is probably the overall weight of the vehicle and the suspension that are the limiting factors.
Here is how I had my vehicle equipped. I would not have attempted this feat with anything less:
1968 El Camino SS-396. Original block and heads. Some engine upgrades including aluminum intake, headers, etc. 4-core radiator with auxillary transmission cooler. Transmission temperature gauge. TH-400 automatic transmission with "switch-pitch" torque converter (1200/3000 stall). 12-bolt rear axle (3.07 posi). All polygraphite suspension bushings front & rear. Super heavy duty anti-sway bars front and rear. '69-style front disk brakes. '75 El Camino rear 11" brake drums (originals were 9"). Custom-bult heavy-duty hitch. Adjustible electronic trailer brake controller mounted on console where driver can manipulate it while driving. Rented trailer with electronic brakes.
I would recommend the electronic brakes over the "surge" type trailer brakes.
I wouldn't hesitate to use my '68 El Camino to tow such a rig in the future. But I probably wouldn't do it for that great a distance - especially alone.
Team Chevelle Gold Member #11, ACES #701
Author of the GMC Sprint, El Camino, and '68-'72 SS Authentication pages.
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