2000 150 4x4 4.6 4r70w trans 3.31 gearing . 38k on the clock

I recently installed bigger tires went from 235 70 r 16 to 265 75 16 noticeable change in gearing ( plan on changing gearing to 373 this summer ) I don't tow much ( small utility trailer ) at most . my question it as follows, is there a product for the transmission that can alter light / mid throttle shift points as in staying in gear longer between shifts ?? I know with a valve body kit I can alter shift firmness ( been looking at bauman valvebody calibration kit $124.00 ) I just feel as the stock shift points are low and sloppy and by raising them if available to do so would allow the drive train to work more effectively . please if there is a way to do this without pulling trans and totally disassembling the transmission while retaining the lock up converter speak up and direct me to manufactures and or suppliers you use and trust . I just recently replaced all trans lines and flushed the entire system no metal , no black , no nothing . fluid red , red and blew out cooler . please advise .. thanks in advance

 

I believe my Superchips tuner will do that. It's been a while since I messed with it. But, I did change the shift points at one time and I think it slowed the acceleration so I put it back to stock. I have a 5.4 2002.

 

You need a programmer to adjust for tire size and adjust shift points.

 

I have looked at tuners and from what I understand about them and transmission function is that they can change shift points and firmness at wide open throttle . not what I am looking for well , not exactly . under light acceleration the trans shifts right up through the gears fast 30mph and in 4th gear I would like to hold on to each individual gear longer . I know back in the day I could modify the valve body in a torqueflite trans to do this and throttle response was alot crisper and the trans didnt have top shift as often so to recap not at wide open throttle ( no sense of spinning the engine any higher just to spin it ) but at light throttle . like cop cars ..

 

A CUSTOM tune can probably do what you want. Contact MPT or another reputable SCT tuning shop. You will need a programmer to adjust for tire size and gear ratio anyway. It's an electronically controlled transmission so that's the right way to do it.

 

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so from what your saying here there is no benefit to valvebody modifications and it is all controlled electrically ??

 

You CAN do it with valve body mods like in the "old days" but doing it with custom tunes is a better way to do it these days, and you don't have to open up the trans. Tuning also has throttle response, overall power, economy, and driveability benefits. You can have multiple custom tunes loaded in the device for different situations (towing, economy, racing, etc.) and fuel octane. The 4R70W is quite responsive to tuning.

 

May as well go for 4.10s if you are changing.

 

that is what I was thinking but I do not think ford ever offered that gearing in a front diff for the 150 . I may be wrong . here in the rust belt there are many to choose from in the junk / recycling yards and being that they are so old I can get entire assemblies for cheap so I would be just swapping them out instead of refitting with new gearing . 390's would be a big jump from 331's

 

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You CANNOT change when the trans shifts by changing anything in the valve body. The decision on when to shift is all in the computer, all the valve body can do is execute the command to shift.

 

I build a lot of these transmissions... almost every one of them has a worn pressure regulator valve and worn boost valve. I install Sonnax replacement valves on all my rebuilds and it really helps the shift timing.

http://www.sonnax.com/parts/2397