Towing Upgrades for the 1987 4.0 Auto

[The Crispinator]

I've got the 4.0 straight 6 from 1987 in automatic, and I'm building a bed camper for it. Any idea how much it can safely haul and what modifications I should do? 

 

edit: Also, should I lift it at all?

[Pete M]

30 years ago they were rated for towing 5k when equipped with the tow prep package (including a trans cooler), 2" receiver, and the appropriate wd hitch and trailer brakes for heavier trailers.   now a days it's a small 30 year old truck with 30 year old parts.   I would focus on brakes and a WJ dual booster with all new everything. 

[omega_rugal]

Heavy duty transmisions cooler and temp gauge, a good temp gauge to keep an eye on the transmision at all times

 

dual diaphragram booster out of an WJ, it doesnt increase the actual braking power but reduces the amount of effort to get full pressure

 

also advisable to upgrade the rear axle to a dana 44 or a 97+ chrysler 8.25 or ford 8.8 out of a v8 explorer, all require some degree of fabbing so i would suggest going straight to the 8.8, beefier and disk brakes out of the box but some spacers or offset rims can easily make up for it

 

if oyu are going to tow, instead of lifting i would suggest adding stronger leaf springs, lifting is more for off roading so you can clear obstacles, not really useful for towing

[ghetdjc320]

Checkout the brake upgrades thread in the DIY section. The liberty 8.25 is a nice swap. Disks, the right wheel pattern, and nice width. That being said, I’ve towed 2-3 tons with my Dana 35. 

[dasbulliwagen]

I agree, better brakes, better rear axle, Metric ton leaf springs, trans cooler, upgraded radiator. Just make sure you see the big picture and address everything that will make it better for your intended use. 

[omega_rugal]

oh yeah, i forgot about cooling

[elliot]

Do you know if 15in wheels will fit on a Ford 8.8 with disc brakes?

[Pete M]

yes they will  

[75sv1]

I might also look into some steering upgrades. If I did a lift, it would only be 2". With spacers for a Ford 8.8, I'd make captured ones, so the need for extended stud screws. Or Yukon makes an upgraded axle shafts. They extend out 1" on each side.  

[gogmorgo]

Because it hasn’t been addressed and we’re talking about a bed camper, payload when new was standard at 1400lbs, metric ton at 2200lbs. Legally that’s all it’s good for, no matter what upgrades you do. 
The difference between the two for the added load is springs, shocks, and rear axle.

For my camper build I was originally planning metric ton springs, although now I’m leaning toward standard capacity springs with airbags in place of the bump stops to keep the ride height the same so I’m not screwing around with headlight aim any time I drop the camper in.

My build’s a long way off though at this point.