im currently running 14.90s on 275/45/20s(29.7" tall), with 3.42s. what kinda improvement would I see with some 26" or 27" street tires on stock 16" wheels?

best 60' I pull on the 20s is a 2.29

 

2tenths is very possible

 

id be happy with that, basically stock truck ecsb with a built tranny, shorties, and a tune running 14.70

 

yep i gained 2 tenths going from 275/45/20s to a 27 inch drag radial on 17s

 

I went from 285/50-20s down to 265/60-18s and picked up an average of about .15 in the 1/8mi.

 

i picked up a set of stock 16" tahoe wheels, what size tires ya guys recommend? they will be basically track wheels. i might try and find a used set of drag radials

 

I'd go with something around 28-30" tall.

 

id like to try a shorter one than whats on it now, it shifts into 3rd about 50ft before the end of the track and seems to lug it down with the big RPM drop

 

With 3.42 gears, I'd find a 26" tire for sure.

 

Are you locking the TC at WOT?

The stock tuning locks the TCC at WOT in 3rd gear. I would upshift into 3rd, then a second later the TCC would lock. I improved by 1 tenth consistently by disabling the WOT TCC application.
Before I got my tune, as soon as the trans went into 3rd, I would hold the brake pedal just enough to illuminate the tail lights, this prevents a WOT TCC application as well.

peace
Hog