Hi, I have an 87 f250 with about 160000 on it, I have the 6.9 diesel NA although I do have a turbo to put in it at some point. I've put in a radiator, revamped the cooling system have done all kinds of maintenance to it including putting in a limited slip 4.10 full floating rear end off of a 94. And I believe I have the C6 transmission. Now my question is, I just took a trip with it hauling a total of 12500 lbs truck and trailer included in that. The trip was about 4 hours each way through mountainous country terrain. The truck performed wonderfully and wasn't bogged down and the rear end didn't sag. So my question is I would like to be able to make this trip once a month or so but I would like to take more with me I would like to have the truck and trailer w/payload to way at least 15000 lbs reliably. What are some more modifications I can do to up its capacity safely. As it is I think I could safely add more weight but i'm not sure how much. Thanks.

 

trans cooler and guages. EGT, trans and water, boost guage if you add a turbo. If you are pulling a trailer add and trailer brake controller.

Watch your speed especially on down hill decents.

 

Let it breathe.... lo restriction muffler ( if any at all) too and a larger pipe to the back.. Get that turbo on ASAP. It's amazing what that will do for your pulling power. I had a Banks kit I put on my old '92 NA. It was a WOW! moment.

 

Thanks for the tips. Any recommendations on a trans cooler? I also have another question since i'm thinking about it. This truck has really hard shifts. My grandfather told me many years ago it had a "shift kit" in it with no more specifity than that. When I accelerate unless I let the engine tach all the way up I have to let off the gas for it to shift. However often times i'll let off the gas to keep the rpm low and shift it when I want however as soon as it upshifts and I apply more fuel It instantly downshifts again unless the rpm are where the tranny seems to want them. thanks again

 

Get the biggest one you can fit in there..... after you get it overhauled. That ain't right...shift kit or not.

 

Your '87 will have the 3 speed C6, and even in stock form, it is a rather quick firm shifting transmission, witch is one of the reasons they lasted so long!




Biggest tranny cooler you get fit! Gauges are also very important, I'd even recommend a trans. temps gauge. Especially since you plan on towing through some hills often with this truck.



You could convert to hydroboost brakes from a same gen. F-Super Duty (F450) truck, witch will make a night and day difference in braking power.