CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

The "Eileen's Fault" build

19880 CC4X4 Dually
Junior has been driving the Ford rental van like a raped rape. Not slowing down up hill, passing semis and just getting after it. Has 2100 pounds in it and his C4 on their car trailer. I have been impressed.

Until I pulled in front of it at the hotel to block it in.

I notice it's a GMC.:doah:How do I miss stuff like that now? Open the hood, label says 6.6L displacement. It's a L8T.

I'm impressed.
 
Junior has been driving the Ford rental van like a raped rape. Not slowing down up hill, passing semis and just getting after it. Has 2100 pounds in it and his C4 on their car trailer. I have been impressed.

Until I pulled in front of it at the hotel to block it in.

I notice it's a GMC.:doah:How do I miss stuff like that now? Open the hood, label says 6.6L displacement. It's a L8T.

I'm impressed.
I hated to crack your bubble when you kept telling me it was a Fraud but you had already posted the picture
 
It’s an old school Crew Cab Square and it deserves a proper old school BIG-BLOCK built for low end grunt work.
L8T’s are cool and have their place but that beauty of a truck ain’t it.

Build another ( not the race worthy hot rod 489 motor ) 1/4” stroke 454 with some oval port heads ( or those cool smaller port Brodix heads ) and a well spec’d hydraulic roller wiggle stick with enough numbers to matter and some F.I. - put a 4L80E behind it and back off the gear to 3.73’s and drive that thing with pride at any speed!

Big block - just do it…just my two cents worth.

BTW, very nice build project and cool parts from Russ - that truck is gonna be sweet !
 
Last edited:
I read about them a couple of weeks ago. Memory not great.
Iron block. Identical numbers as a 6.2, but a forged stroker crank.
The L8T has a smaller cam so it makes the power and torque at a little lower RPM.

L86 is 420 HP 460 TQ, 6.2L 376 CID
L8T is 401 HP 464 TQ, 6.6L, 401 CID, but it shifts the peaks down a couple hundred RPM or something, am sure it has more torque below 3000.

Both have DI and VVT so that helps with torque curve and efficiency

The L8T does not have DOD or AFM or any cylinder deactivation bullcrap, the L86 does.

The L86 has 12.5:1 compression recommending premium fuel.
The L8T has 10.8 I think and recommends regular fuel.

My Sierra 1500 everaged 18 MPG not towing, sometimes as high as 21 MPG country driving. Towing MPG ranged from 9.5 - 14 MPG

My Silverado 2500 averages 14, maybe 15 MPG not towing, highest I have ever seen is about 18 mpg but not for long. Towing MPG ranged from 8 - 11 MPG.

The 2500 weighs literally another ton (7400 lbs vs 5500 lbs)

I've owned and driven both, and multiple SBC and BBC.

The L86 1500 was way more sporty and fun to drive, the L8T 2500 feels like a tank, just the transmission (10L1000) and shifting parameters make it feel like a tank. One thing that was hilarious. I pulled out a stump with my 2500. I was on my gravel driveway, hooked up log chain, put 2500 in 4WD low range, and trans in 1st gear. And gave it a touch of throttle and pulled out a stump 6" diameter that went down about 5 ft and tore off.

Then I hooked to a larger stump, of course it stopped the truck even after some light throttle application.(not willing to shock my new truck too hard when the chain tightens, its violent) But the funny thing was, with all that gearing and torque, after I let off the throttle, the truck would keep spinning all 4 tires in the gravel with no throttle!

Everything has its pros and cons. For these DI engines, they are quite efficient on mileage, but for raw torque and power, the BBC is still king.

I think that truck will be happy with either an EFI BBC/4L80E or an L8T/10L90E, I don't think you can go wrong with either. It depends on what you prioritize.

Now, if you are comparing everything bone stock, the way it came, both those new DI motors are extremely impressive, the BBC needs upgrades to really shine.
 
Last edited:
The L8T has a smaller cam so it makes the power and torque at a little lower RPM.

L86 is 420 HP 460 TQ, 6.2L 376 CID
L8T is 401 HP 464 TQ, 6.6L, 401 CID, but it shifts the peaks down a couple hundred RPM or something, am sure it has more torque below 3000.

Both have DI and VVT so that helps with torque curve and efficiency

The L8T does not have DOD or AFM or any cylinder deactivation bullcrap, the L86 does.

The L86 has 12.5:1 compression recommending premium fuel.
The L8T has 10.8 I think and recommends regular fuel.

My Sierra 1500 everaged 18 MPG not towing, sometimes as high as 21 MPG country driving. Towing MPG ranged from 9.5 - 14 MPG

My Silverado 2500 averages 14, maybe 15 MPG not towing, highest I have ever seen is about 18 mpg but not for long. Towing MPG ranged from 8 - 11 MPG.

The 2500 weighs literally another ton (7400 lbs vs 5500 lbs)

I've owned and driven both, and multiple SBC and BBC.

The L86 1500 was way more sporty and fun to drive, the L8T 2500 feels like a tank, just the transmission (10L1000) and shifting parameters make it feel like a tank. One thing that was hilarious. I pulled out a stump with my 2500. I was on my gravel driveway, hooked up log chain, put 2500 in 4WD low range, and trans in 1st gear. And gave it a touch of throttle and pulled out a stump 6" diameter that went down about 5 ft and tore off.

Then I hooked to a larger stump, of course it stopped the truck even after some light throttle application.(not willing to shock my new truck too hard when the chain tightens, its violent) But the funny thing was, with all that gearing and torque, after I let off the throttle, the truck would keep spinning all 4 tires in the gravel with no throttle!

Everything has its pros and cons. For these DI engines, they are quite efficient on mileage, but for raw torque and power, the BBC is still king.

I think that truck will be happy with either an EFI BBC/4L80E or an L8T/10L90E, I don't think you can go wrong with either. It depends on what you prioritize.

Now, if you are comparing everything bone stock, the way it came, both those new DI motors are extremely impressive, the BBC needs upgrades to really shine.
That is what I wanted to say but couldn't.
The only complaint I have seen is the noise. They are loud injectors.
 

Latest Posts

Top Bottom