Alright, this has been bugging me for a while, and I'd really like to fix it. What do I have to do to be able to go WOT in 4th? As it is now, it doesn't matter how fast I'm going (120MPH, or whatever) if I hit WOT, my car downshifts to 3rd.
What can I do to fix it?
Last night I got to run my first 1/4, and at the end I was close to 6500rpm in 3rd. I think if I could get into 4th at WOT I could shave off a few extra .1.
Any ideas?

 

you have to be running at less than 70% throttle for the trans to shift into OD. i know B&M makes a part that will allow the trans to shift into od at full throttle, i just cant find the PN right now.....

 

The GM part no. is 8673948. If you do install this part you may have to recalibrate the governor and the 3-4 shift timing spring because it will go into overdrive to early and bog down the motor.

 

You want to be at redline when you pass the traps....when does your motor stop making power? Any adjustments may need to be made in your rear gears. OD is not for the 1/4...just a thought.

 

Good point Riley. I didn't read far enough into it, only the basic answer. Perhaps 3.42's would be a better choice?

 

You were at the top of third gear BEFORE you hit the big end with 3.73 gears & you only ran a 14.3 ? Something is wrong with this picture.

 

Yah, but remember my altitude kinda sucks here at 4500 feet. Altitude corrected my time was 13.5 at 100.
And it was my first time, so I don't know if I was shifting at quite the right points.

 

Something just doesn't add up, I agree. I go through the traps in third gear, somewhere between 4500 and 5000, doing 103 MPH and I have 3.73s. I wonder if you have some slippage (either in the transmission, or a real high stall converter)

 

Well, my stall convertor was supposedly in the 3000rpm range, but I can usually only stall it up to about 2500rpm before it starts spinning the back tires.