can you make it otr in a 87' with a big cam

Not sure what the 9-oo will do with lopro tires and 4.10 rears but age wont hurt you unless you try to lease it on somewhere or try to put an employee-driver in it.Key is gonna be fuel mileage.

 

I'll bet it will run faster than that motor will pull it loaded.

 

Good gearing for hills and city traffic- hope you do well for mileage.

 

I did fine with a 84 4300, big cam III and a 15 double over. 3.70 rears. Your geared good for running in the hills but I think your going to suffer on flat lands with mileage. I was around 5- 5.5 with mine

 

I would only look for a truck if you don't think your 87 is in good enough condition motor tranny and rears are important, but I talking more about general condition such as suspension, steering, framing. To tell you the truth and I think other o/o would agree, that truck will run circles around the newer trucks if in good condition. That motor was designed to do exactly what you are wanting to do.(heavy haul). The metal that was used to assemble the truck is manufactured at a higher grade. The newer trucks have lower steel standards due to budget cuts. I don't want to discourage you from a newer truck b/c the newer ones do have their own pro's.
I am bias in this discussion I run a 85 359 with a 15 spd 3:55 rears. I get 5.9 a gallon. Truck is on high rubber that also makes a big difference at cruising speed.

Don't know if this helps, good luck and let us know what you do

 

pulling an RGN and or stepdeck you will most likely get poor mileage with just about any truck regardless of the year and engine etc. with your truck i would expect 4.5 to 6 mpg max, yes 1 mpg make a difference but so does a big truck payment. as for the age, if it is in good condition i would run it. 10 years ago I ran a 1979 GMC Astro cab over, over the road out of Montana pulling a grain hopper. It had a 6v92 detroit 10 speed and 390 rear ends. for the same little company I also drove a 1976 international transtar, It had a 370 hp, 3406 a model cat 13 speed and 390 rears as well. we ran west of the mississippi. the only issue I have ever had with old trucks is the fact that the shops out on the road can not plug them in to diagnose problems, thus leaving some of the newer Mechanics wondering how to find the problem... I would run it..