That is what I do. Leaving my house it's a long straight road (with a 55mph speed limit) in drive it takes a quarter mile to get to 55. If I manually shift it I'm running 55 way before a quarter mile.

 

I do manually shift it when i race it.. thats what im saying i can wind 1st as far as i want to but 2nd shifts itself out all on its own.. at 4 to.. im runnning an 89 gt motor it can handle more than 4 gran.. ill prlly just put a diff. transmission in it

 

if it's computer actuated it may be the ECM making it shift.... or there is an issue with the trany... I'd ask a tranny shop about it....

 

well the one thing yall are forgetting is..

is it an AOD???

if it's an AOD you can get a shift adjuster that'll bring shift points up to like 5600 Rpms..

thats what i'm doing along with a shift kit..

but you gotta make sure your truck makes power up there or else your wasting..

 

that doesnt always work....

if the trany has been previously modded for towing the change wont work...

 

As of right now its an 89 gt block with gt40p heads/flowtechheaders/true dual flowmasters/under drive pulleys/TB spacer/msd ignition kit/k&n cold air intake/stock 3.55 gear.. here soon ill be puting electric fans and 3.73 gears under it and poss. having intake ported but still debating on HO intake conversion. also traction bars as of right now the trucks pretty fast when it hooks.. its fooled alot of people but that 2nd into 3rd shift kills me

 

WHAT TRANSMISSION do you have??????

thats the key point im asking.. thats how you know what you can do to adjust the shifts...

 

I ran the numbers along time ago and believe it came back as an AODE but im not forsure ill check it out tom. and post what it comes back as.. the door jam sticker code for trans reads T but not to trustworthy.

 

Trans code T is an AOD.. Non electronically controlled..

The column shift indicator goes P R N (D) D 1 doesn't it

(D) is drive with overdrive. D Is drive with overdrive locked out...

I have been wondering as we'll about the shift from 2nd to 3rd on how you'd do it manually but not been to worried about it as I have my points adjusted well..

Like I said above on a AOD You have to install a shift adjuster to bring up the shift points
Like I said before this makes a world of difference in this issue..

 

Have another transmisson quetion.. What would cause your truck to try to pull while in neutral reving motor?