Hey guys, I have a friend who has a stock 4.8 rclb 2wd with 235/70/16's. I have a 5.3 ecsb 4wd on 17's with 285/70/17's, I also have a Wheatly tune. We did a roll from 55, I was already dropped in 2nd gear and he wasnt. So I got a big jump on him then he shifted to 2nd and began to catch me and by the time we were at 85 he went from being a full length behind me to his nose at my door. Why is his stock 4.8 catching my tuned 5.3. Is it just the extra weight of the ec and the 4wd or a combination of that with the 285/70/17's. Thanks for the replies guys.

 

Your extra weight of 4x4, larger tires, ext cab, and catching more air being at a higher ride height, thats all working against you the faster you go. Seems about right to me. Your lucky he didnt beat you.LOL

 

He could have 3.73's and you 3.42's,plus you have alot more tire weight than him....

 

so smaller tires and lowering the truck will do a little but not that much. I think if we kept racing he probably would have passed me slowly.

edit: I also have a z71 and do the z71's come with 3.73's? he has a 2004 sierra work truck model so i dont know if that would affect what gears he has.

 

Putting on smaller tires is like putting in lower gears.

 

4.8's are stout motor's...

 

My buddies stock ECSB z71 will pull me by half a truck or so in third gear. I have a tune and headers, but I'm also on heavy 18s and 33s. Race him from a dig or 20-30, You should pull away pretty easy then.

 

Weight and gear play a huge roll.4 wheel drive also!!
Your tires are 31.7 inches while the 4.8 truck tires are 29 inches.That also makes a difference in the overall ratio

 

time to sell the tires!!

 

I bet his 4.8 has 3.42's.Seems most do but, regardless i would not be dissapointed weight was the biggest factor.My truck stock did well against my partners stock 03 ss from a roll.If i had 4.10's i think it would have been neck & neck.