LB7: 1200HP build

02ilduramax

Member
Jun 21, 2011
632
3
18
fulton,illinois
looking for suggestions of what all is recommended in a 1200hp build as far as internals go I have carrillo rods already and the block is .020 over truck will be drag race only possibly nitrous occasionally
 

slowlml

Undercover Epa agent
Feb 6, 2015
577
53
28
Strasburg Va/Wardensville Wv
Do some searching on here for what similar builds have done. Im sure some guys will chime in though. I would definitely go with fingers cast pistons, 425s or 625s on the head depending on your air setup, key cam and crank, girdle of your choice. If youre doing a cam can go af but in my opinion i dont think it helps much. People still snap them. The big money cranks havent been the fix alot hoped for either so whatever your pockets feel like doing there. Fill in the blanks with arp hardware for main studs etc.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,743
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Phoenix Az
LBZ block or newer
SoCal marrow rod journal crank
fingers cast pistons or your choice of forged pistons
H or HX bearings
Large cam to match the large single and heads you plan to run.
Heads I would not run stock w/ ported, since i can only assume it’s the lb7, I would start with edlebrock heads and port those. Stock when ported tend to crack easily
O-ring the block and run your choice of head studs
Key the typical crap
Run a higher volume oil pump
Girdle and billet caps are your choice.
Don’t run a billet flex plate, use a BD if you want to upgrade
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
LBZ block or newer
SoCal marrow rod journal crank
fingers cast pistons or your choice of forged pistons
H or HX bearings
Large cam to match the large single and heads you plan to run.
Heads I would not run stock w/ ported, since i can only assume it’s the lb7, I would start with edlebrock heads and port those. Stock when ported tend to crack easily
O-ring the block and run your choice of head studs
Key the typical crap
Run a higher volume oil pump
Girdle and billet caps are your choice.
Don’t run a billet flex plate, use a BD if you want to upgrade

Why not a billet flex plate? Seems like the one Guy has would be a good choice especially since it saves some weight on the rotating assembly.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
It’s not helping rear main bearings or thrust bearings with a converter attached. Mahle/clevite need to come out with better bearings... only so much can be done.

This is not falling in line with the Callie’s thrust bearing issue, it’s something else that has slowly been coming up more.
 

1FastBrick

Well-known member
Dec 1, 2016
2,600
1,117
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Junkyard
It’s not helping rear main bearings or thrust bearings with a converter attached. Mahle/clevite need to come out with better bearings... only so much can be done.

This is not falling in line with the Callie’s thrust bearing issue, it’s something else that has slowly been coming up more.

Thanks! :thumb:
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
So how much axial thrust does the Allison/drivetrain create? I know manual trans assemblies create a lot of axial thrust that beat on thrust bearings. So I’m thinking then that the stock or BD flex plate does just as name implies, flexes and dampens the thrust load that would be put on the rotating assembly to help the bearings? Mainly thrust? More of an issue for vehicle that are doing only drag and boosted launches? Sorry OP for taking up some of your thread with my questions
 

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
It’s not helping rear main bearings or thrust bearings with a converter attached. Mahle/clevite need to come out with better bearings... only so much can be done.

This is not falling in line with the Callie’s thrust bearing issue, it’s something else that has slowly been coming up more.


Post some pictures of what you are seeing please. I personally haven’t seen a issue so far with the billet flexplate and having a bearing issue.


Sent from my iPhone using Tapatalk
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,743
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Phoenix Az
I have none to post that are my own. The other shops may do so if they would like (not my place). I’ve only used stock or BD flex plates in the builds I’ve done with no issues.
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
4,224
1,326
113
Larsen, Wisconsin
LBZ block or newer
SoCal marrow rod journal crank
fingers cast pistons or your choice of forged pistons
H or HX bearings
Large cam to match the large single and heads you plan to run.
Heads I would not run stock w/ ported, since i can only assume it’s the lb7, I would start with edlebrock heads and port those. Stock when ported tend to crack easily
O-ring the block and run your choice of head studs
Key the typical crap
Run a higher volume oil pump
Girdle and billet caps are your choice.
Don’t run a billet flex plate, use a BD if you want to upgrade

^ This. A single is much easier on the bottom end than a set of compounds or triples simply because they tend to not build as much power down low.

Unless brad sold his turbo already id go pick his up. He did 1300+ on it as a single at high elevation

It did 1340/2200 corrected at 7800DA in the dyno cell on 1800us with Exergy modded 250s with a 0.041" and 0.088" jets (one each). The next day it went 126.85mph @ 7620lb @ 8800DA which put it at 1055hp to the tire on a single 0.062" jet. That was on a Forced Inductions V4 ETR 480/96/1.10 T6 with a Borg V2 race cover.

If someone's goal is to build a race only truck that won't be street driven its a fun setup. I knew it was going to be lazy on the street, I just didn't realize it would have been as lazy as it was.
 

D_Ferrante801

I hate everyone.
Apr 2, 2019
66
34
18
^ This. A single is much easier on the bottom end than a set of compounds or triples simply because they tend to not build as much power down low.



It did 1340/2200 corrected at 7800DA in the dyno cell on 1800us with Exergy modded 250s with a 0.041" and 0.088" jets (one each). The next day it went 126.85mph @ 7620lb @ 8800DA which put it at 1055hp to the tire on a single 0.062" jet. That was on a Forced Inductions V4 ETR 480/96/1.10 T6 with a Borg V2 race cover.

If someone's goal is to build a race only truck that won't be street driven its a fun setup. I knew it was going to be lazy on the street, I just didn't realize it would have been as lazy as it was.

T6 on a duramax is not fun period. Unless you like to daily drive with a spool jet 24/7 and even then is not enjoyable. I even did some secret squirrel shit in your file to ATTEMPT to help spool up LOL.
 

Bdsankey

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Feb 1, 2018
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T6 on a duramax is not fun period. Unless you like to daily drive with a spool jet 24/7 and even then is not enjoyable. I even did some secret squirrel shit in your file to ATTEMPT to help spool up LOL.

Honestly what ever you did worked well at sea level. At elevation it wasn't happy. With that said, I would argue on a dedicated drag/puller it would be much more ideal than a street truck as big single chargers are easier to work on and easier on hard parts.