i went from a 14.20 to a 14.007 buy pulling the headlight, and took the filter off the cai, worth a try man, it was also 54 degrees out that day....

 

When the tc and stabilitrac are disabled, it will still apply the abs if wheelspin occurs. I do think the difference is in the weight of the vehicle though, and not just static weight but the rotational mass of the larger wheels has got to be sapping the power.

 

I believe stangkillr said he gained considerable mph by upping his shift points, and is shifting somewhere around 6500-6700. Search for his old thread, info is in there somewhere..

 

6500 - 6700 is way too high for a stock cammed 6.2.

 

It looked to me like you had good numbers on the dyno, so I wouldnt be too worried about converters and your muffler. Patrick should have the best information as to why the times arent there like you want them due to the fact that he tuned it. What was the day like when he tuned it compared to the day you ran at the track? What gear and RPM's are you going through the traps at? I will agree with most people, and you do need to get off of the line a lot better. The rotational mass of the tires/wheels will make a difference, but in my opinion the height is a bigger factor. Have you thought about a converter?

 

Again Im not 100% sure on that, but i think thats what he said he tried shifting at.
Imo is 6700 too high, yes. Now is 6200-6500 too high, im not so certain it is. These 6.2 dynos dont show a huge drop off in the graphs from what ive seen to call for such a low shift point..

 

i shifted my stock cammed 5.3 at 6500...and 6 years later im still the only one to hit a 13 second pass in an extended cab stock cammed 5.3....although i probably could have run the same exact times shifting at 6,000 lol. you just gotta play with it.

 

my 17's with the all terrains are not as light as you might think. some gm 20's w/tire are lighter.

use the dyno graph to determine your ideal shift point. mine is 6100

 

Can't go wrong with a Banks ram air kit. I was more than impressed with it. give er a shot.

 

Mucho thanks for all the replies and suggestions, guys. Genuinely appreciated!

After sleeping on things - here are my initial plans . . .

3.73 gear, and most likely install a gennie LSD instead of that awful OEM gov-lock diff

Stay with my 20s, but pony up for a new set of stock P275 tires

Consider airbox mods and / or a high-flow filter

Check exhaust system back pressure to make sure I don't have restricted cat(s)

Hire Patrick G to double-check my tune, and of course update for the 3.73 gear

Pull some weight out - at least the spare tire and possibly the tailgate

Opinions are welcome, and thanks again!