Need Advice: OBS Suburban 2500 7.4L vs NBS Suburban 2500 6.0/8.1L

[camaroz1985]

Go with the 800 like others have said, and if you want something you can tune and fiddle with, get the 6.0. The 8.1 can be tuned, but there aren't nearly as many parts as you will find for the LS based 6.0. As far as transmission, you only get the 4L80 with either choice, the Allison wasn't offered in the Suburban (not standard or as an option).

From the research I did before buying, the 6.0 and 8.1 only are about 1-2 MPG different in these trucks. I have the 8.1 with 4.10 gears, rated to tow 12k lbs. I have never towed anything that heavy, only about 6-7k, but even in stock form the engine has plenty of torque to get that moving with ease.

 

[Diggerdan11]

Go with the 800 like others have said, and if you want something you can tune and fiddle with, get the 6.0. The 8.1 can be tuned, but there aren't nearly as many parts as you will find for the LS based 6.0. As far as transmission, you only get the 4L80 with either choice, the Allison wasn't offered in the Suburban (not standard or as an option).

From the research I did before buying, the 6.0 and 8.1 only are about 1-2 MPG different in these trucks. I have the 8.1 with 4.10 gears, rated to tow 12k lbs. I have never towed anything that heavy, only about 6-7k, but even in stock form the engine has plenty of torque to get that moving with ease.

Hmmm Yeah I thought based on research they never came with the Allison. Like I said I have had experience with the 8.1L and it is a beast, but probably more than I need. But of course Bigger is Always better, and there is not replacement for displacement LOL


I have seen a bunch of 8.1's for sale for under $6,000 but they usually have 200K+ miles. Is there anything I should be worried about with that high of Millage? The Highest Mileage vehicle I have ever owned had 140K and that was my 03 Tahoe and it had some transmission issues. Now I know the 4L80 is a much better tranny than the 4L60/4L65. I know from my Silverado SS days that most people seem to think a Stock 80 is stranger and more reliable than even a fully built 60/65