I have a 6.0 in my 2000 2500. It has 65,000 on the engine. I have added LPP long tubes with ORY and 3 inch magnaflow exhaust, 8.1 marine injectors, 243 heads, ported and polished tb, and an EPS cam. The cam specs are 218/226 at .050 .598 lift on a 114 lsa with 4 degrees advance ground in.

At the dyno tune, it only put down 305 hp at the wheels. I was hoping for 330 or so. My tuner attributed it to the reciprocating mass of the 4L80 transmission, 14 bolt rear axle, and the 12 ply mud tires. Does this sound reasonable? The truck is definately faster, but still feels soft in the lower rpms. Oh yeah, I am also running a yank 2400 stall converter.

 

True, running a 4L80E will yield lower results vs a 4L60E, but with you being a heavy truck you gotta have that heavier duty transmission. Each dyno yeilds different results as well to the next one.

Take it to the track first and get some times, its not all about the dyno #'s.

Also about it feeling kinda soft still on the low end, maybe you should of went with a 2800 converter at least, but I am sure it runs fine with the 2400 you have now.

 

How does it run on the highway? You might look into a different torque converter from my readings here changing converters makes a difference.

Yes the 4L80 is the root of your no power it is a pig of trans on horswpower.

 

What are the details on your wheel/tire package?

 

3.73 or 4.10's and what size tires? Being a 2000 it's a non HD so it could be either or. And honestly since I can flash my 05's stock convertor to 2500-2600 rpm why would you go with a tighter convertor than stock with a bigger cam? As mentioned these trucks aren't light and the 4L80E uses a bit more power than a 60E....... but then doesn't explode every other day either. I wouldn't mind at least a 3000 or 3200 in my 1500HD's 80E but then I only have 3.73 gears as well. 4.10's would help but aren't worth my time to switch honestly.

Dyno's don't honestly mean $hit without a stock reference point so don't even look at that. A looser convertor and no doubt some gearing would probably help with your soggy bottom end.

 

don't those 243's lose some compression unless they're milled like on a 4.8 or 5.3?

 

Gain compression on a 6.0, 317 have a 71cc chamber vs 64cc on 243. 4.8/5.3 have a 61cc chamber.

 

i was thinking i had the backwards, thanks for the clarity. Buddy of mine put 243's on his 5.3 and it dyno'd under 300 horses cause of the compression loss

 

The truck has 3.73's. I built it as a towing rig, hence the mild converter and cam. My tuner overlayed my results over a stock 2001 6.0 and the difference is about 80 rwhp, and much improved torque throughout the run. Right now im running 285/70r 16 mud terrain tires. A switch to 4.10 gears is coming asap. Im not unhappy with the way it pulls my trailer's, but expected a little more. I do wish I had went with a higher stall, but the guys at Yank suggested this converter for my purposes. For what I did to it, my tuner was fairly impressed, and he knows his ****. I think a 408 build is in my future. Ill try and post my dyno sheet tomorrow.

 

I see. Yank basically sold you a stock replacement torque convertor so unless yours was bad initially you could have saved some cash there. 4.10's will help a bit with your 32" tall tires on the truck but it's still not going to pull really hard down low. 4.30's would probably be about just right but by the looks of things you have the choice of 4.10 or 4.56. Good luck with the truck.