So I went away on a training trip and spent the night at my buddies. Of course, we starting talking trucks (he just redid a 77 hi-boy crew cab. What a beautiful truck) and I tell him I love my truck but it needs to be bigger. He says that his wife works with a fellow that wants to sell some tires but can't find anyone to buy them and thinks that they were 33's in great shape. So I tell him to call the fellow and bring them to town the next day so I can look at them. Well, I get there the next day and he pulls out a set of brand new (still with the little tabs attached everywhere) Kumho mud terrains on chrome rims. So I think, man those are some good size tires. I look and they are 35's. And to top it of they came off a 87 F-150 so they should bolt right onto my rig. And the best part, I ask him how much he wants for them and he says $600 for everything. So needless to say, I grabbed them.

So I have the tires, now I need the lift. I just bought a 6" lift and it should be here in a couple of weeks.

My question to y'all is what gears am I going to have to put in my truck to run these puppies? I posted this question a couple of weeks back but I was thinking 33's at the time. I have the 300 6 with the M50D manual and 3.55 in there now. Reg cab, 7ft box, 4x4. I don't plan on hard core wheeling the truck and it is my daily driver, but I want enough torque to pull trees and crawl while hunting. On the hwy I never go over 110 km/h (can't afford the tickets). I was thinking 4.56's. Is that going to be too low? Thanks for all the help.

 

Your on the right track toward fryin the damned M5OD, 4.56's would work well,the 300 is a tourqey motor, your gas mileage will drop, there are gearing calculators all over the place, just search for one on google, i'd start searchin for a 4 speed to replace it, or if you want an auto a C6, the M5OD fails enough without the extra stress of 35 inch tires.

 

sounds fun, get some pics of it soon.

 

you best invest in a better tranny first! i'd stick with 3.55's. i have a buddy with the I-6 and some 35's and he does very well. that motor will compensate very nicely.

just stick with 3.55's or lower depending on what you wanna do

-cutts-

 

I have heard of some guys on this site running 35's with the I-6 and 3.55, but they all have the lower geared trannies. My thought is that if I had one of the other trannies, I would stay with the gears. I guess what is the better risk, spend the coin on new gears and have the tranny go and have to put the same one in, or stick with the gears and save the coin for when the tranny goes to put in a lower geared one.

I am not going to wheel this truck really hard as I need it as a daily driver, I just want the same torque and crawl that I have now with the 30's and the 3.55's.

 

taller gears are stronger, by lowering your gear ratio you reduce your strength, its best to get the lower ratio from the tranny if possible, find a 4 speed and you can use first as a regular gear instead of granny low, if you find one from a junkyard you'll save some coin too.

 

Thanks for the advice Lead_Foot. What would you recommend for a replacement tranny? I do not want an auto.

 

if you want overdrive i'd look no further than a ZF series 5 speed. some came behind the 5.8's for a small block pattern so i dunno if the tranny will bolt behind an I-6 or not. if ya can just grab the 5.8 and ZF (found in the heavy duty ford pickups from late 80's to late 90's)

-cutts-

 

NP 435's go in and those are really good but they have no OD. I dont know if there are any ZF's that go into those... perhaps someone else will know about that.

edit: fishy's fast...

 

Wouldn't a ZF bolt right up to the bellhousing on a 300? I've never dealt with a ZF before, but I'm assuming it'd bolt right in, with the exception of maybe having to make or find a different tranny crossmember....

 

see i dont know, because in the early 90's they had the ZF for heavier duty applications and a Mazda 5 spd for small er engines, but I dont know where Ford drew the line for HD...

 

Yeah I'm not sure either. I know I pulled my NP 435 out of an '84 F150 and bolted right to my bellhousing on my 390 (was a T-18 2wd tranny) and it worked out great.

So I'm just assuming that as long as he has the Mazda 5spd bellhousing, he could get a new throwout bearing and bolt the ZF right up......Someone has to know for sure.

Either way I believe he would be fine running the 5spd he has now, since he isn't going to pound on it too bad.

 

taller gears are stronger, by lowering your gear ratio you reduce your strength,







how do you come to this??????? a taller gear will make the entire drivetrain work harder , which puts more stress and load on all the parts. a deeper gear would make it easy on the drivetrian and reduce stress and load. it would save the tranny a lot of work also.

 

it will make more work, but the actuall gears are thicker, therefore stronger.

 

the taller the gear the fewer the teeth on the pinion and on the ring too ( i think) which means more metal...