bryson711

How fast does your guys truck go at what rpms? I have a getrag 5 speed and dana 70 with 3.55, my truck seems like it has to run alot of rpms to get to 75 or 80 im up in the 2500 range? Have you guys with the nv4500 swap noticed a difference in lower rpms with doing the tranny swap?

dieselJon

They have the same 5th gear ratio. IIRC it is .75:1.

My old 93 4x4 with 4:10's maxed ran about 80mph or so...

My other 93 2wd ran 90-95 maxed out.

92betsy

Not sure about rpm's but I can go past 100mph. I slow down when it hits that though.

Crossy's son

You need to back out your throttle limited screw, You'll see what I am talking about when you move the throttle by hand, the lever on the pump will come back and hit a screw end, The screw i am talking about is directly opposite of the idle screw.

Back that all the way out and you should be doing 90 at least....Then put in a 3200 rpm governor spring and you should easily do 100 then.

pulltilbroke

I can go well over 100

jimbo486

Well my tach reads high by about 300RPM (where it starts to, I don't know) but in 6th (for me, at .73:1), 3.54 rear end and 235/85/16 tires at about 2,700RPM (3,000RPM according to the tach), I'm doing 100mph. Sure sounds like I'm turning 3,000RPM though!!

Moparbubba

Ole shakey can peg the speedometer well over 100.... 3200gs no screws and 265/75 16s need a tach but she screams

bryson711

Im beginning to think that my truck has had a gear change sometime with a previous owner, my vin says it cam factory with 3.55 but I think it has 4.10 in it, it has a 3200 kit in it know and I can get it to do 90 or 95 but it is rapped out with all the rpms it can handle to get it too that point, I think im gonna pull the rear diff cover and start counting teeth and figure it out for sure

RonA

Back when I still had the VE motor, I hit 92.5mph in 5th overdrive(gear vendors). Took about 2 miles of straight road to go from 70 to 92.5.

bryson711

I know the guy that originally owned my truck before I got it five years ago, im gonna go to his house right now and ask him if he has ever changed them before I got it, it really does not seem like 3.55 to me

Crossy's son

That sounds normal if the throttle limiter screw is in the stock position.....

Crossy's son

I can almost guarantee noone went through the work to change front and rear gear ratios, if they did. they're crazy. These things have plenty of torque to power through even the lowest gears you could get.

bryson711

Well I just got done talking to him he had the axles rebuilt but has never changed the gear ratio, so it does have 3.55, so I guess my next question is is what can you do to get more top end without using so much rpm? Im guessing probably just going to a bigger tire right now I have 235 75 r16

dzl_damon

if you need top end for some reason, then get some 3.07 gears/axles from an 89-91 automatic Cummins with the 727 3 speed.

They are technically Dana 71 rear ends, so you can't just swap gears.

Unscrew that throttle screw like everyone is telling you. It will be one of the best 2 minutes you've spent on your truck! Mine was actually screwed IN from the previous owner. I was maxing out at 2300rpm or so. Guess he couldn't figure out which one was the idle adjustment since it also had a high idle from messing with the fuel screw.

454 no more

Mine were switched from 3.55 to 4.10, the original owner had it done. I thought about switching back as he had the original gear sets, but I'm going to go to a bigger tire instead. 93 250, tops out at 119 kmh,