Gear ratio vs speed change
 

Thinking of changing gears in my 93 f-150 4x4 rc stepside 302 e4od for pulling my holiday trailer easier(its a big girl 32 ft long and 12000 lbs). I did a maiden voyage the other day and wow it did not too bad at lowwer speeds, up to 80km but over that it was not pretty, I need either another 100hp or lower gears. my question is if i drop down from my current 3:55 gears to a 3:73 set, how much would my rpm change. currently i travel at 100km at 1800 rpm. Thanks

Let me know where you are going, so I can stay out of the way. You are way overloaded, don't waste the money putting gears in the 1/2 ton go out and get yourself a 3/4ton atleast.

i agree with Digger6.you need at least a 3/4 ton,plus you will burn that 302 out.the I6 or 351 or larger would be a better choice,longer stroke more torque,thats what you will need to get that trailer moving.the 302 is a short stroke big bore engine,great for high rev's not bottom end torque.plus your truck won't have the breaking power to slow all that weight when you will need it.the difference on the brakes between my f150 and 250 is like night and day.have fun.

Better choice i will just use my 3/4 ton diesel to pull it around, just wanted to see if i could make it work or not to have two trucks able to pull it around or not. problem solved. thanks for the input