Can anyone tell the difference?

Reply Subscribe

Thread Tools

Search this Thread

Sep 12, 2013 | 12:35 AM

topgun542

Thread Starter

TECH Regular

iTrader: (6)

Joined: Apr 2010

Posts: 474

Likes: 2

From: STL

Can anyone tell the difference?

I cant tell if this is a th400 sbc converter or a th400 to ls1 convertor...

Sep 12, 2013 | 07:58 AM

Circle-D

FormerVendor

iTrader: (21)

Joined: Feb 2006

Posts: 2,474

Likes: 14

From: Houston, TX

Pilot looks to short to fit a LS crank. Can not tell on the bolt circle. Do you have any LS flexplates you can test fit?

Chris

Sep 12, 2013 | 11:57 AM

topgun542

Thread Starter

TECH Regular

iTrader: (6)

Joined: Apr 2010

Posts: 474

Likes: 2

From: STL

I Do, Im Just In College Now So I Forgot To Check When I Left, But I Need To Order A Sfi Flex Plate For When I Go he

Sep 12, 2013 | 11:56 PM

Jake's Performance

FormerVendor

iTrader: (2)

Joined: Oct 2010

Posts: 1,774

Likes: 24

Looks like an LS pilot to me....

Sep 13, 2013 | 02:52 AM

SnIpEz

TECH Resident

iTrader: (4)

Joined: Sep 2009

Posts: 979

Likes: 13

From: League City, TX

Looks like an LS pilot to me as well, but it's hard to judge from the first picture and the second picture obscures it a bit.

Sep 13, 2013 | 03:52 AM

Circle-D

FormerVendor

iTrader: (21)

Joined: Feb 2006

Posts: 2,474

Likes: 14

From: Houston, TX

Yes, very tough to tell from the pic. An LS pilot needs to extend about .500-.550 from the pad of the converter to properly engage in the crank. You should be able to measure that fairly easy. FYI the typical SBC will only extend .200-.250 from the converter pad. And if you can get a measurement from center of one bolt hole to the next, we should be able to calculate the bolt circle from there.

Chris

Nov 9, 2013 | 02:09 PM

topgun542

Thread Starter

TECH Regular

iTrader: (6)

Joined: Apr 2010

Posts: 474

Likes: 2

From: STL

heres some pics of an ls flywheels with the unknown torque converter. the holes are off by about 1/4 in

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Verdad Gallardo

6 Common C5 Corvette Failures and What's Involved In Repairing Them

Pouria Savadkouei

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Verdad Gallardo

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Pouria Savadkouei

Top 10 Most Powerful Chevy Trucks Ever Made!

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Verdad Gallardo

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Verdad Gallardo

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Verdad Gallardo

10 Camaros You Should Never Buy

10 LS Engine Myths That Refuse to Die

Verdad Gallardo

Nov 9, 2013 | 03:49 PM

topgun542

Thread Starter

TECH Regular

iTrader: (6)

Joined: Apr 2010

Posts: 474

Likes: 2

From: STL

what would the pilot extension look like? any site will have them?

Nov 9, 2013 | 06:48 PM

#10

oldtimelt1

Teching In

iTrader: (1)

Joined: May 2009

Posts: 32

Likes: 0

From: west georgia

Not sure but maybe this;
http://www.speedwaymotors.com/GM-TH3...ter,64394.html

Nov 9, 2013 | 07:00 PM

#11

mrvedit

Moderator

Joined: Aug 2010

Posts: 7,323

Likes: 529

From: Ann Arbor, MI

Just reading about this in the January 2014 issue of Super Chevy Magazine, page 48.
They mention GM spacer # 12563543:
http://www.jegs.com/i/GM-Performance...63532/10002/-1

And longer crank bolts #11569956, quantity 6.
http://www.jegs.com/i/Chevrolet-Perf...69956/10002/-1

Nov 9, 2013 | 11:56 PM

#12

topgun542

Thread Starter

TECH Regular

iTrader: (6)

Joined: Apr 2010

Posts: 474

Likes: 2

From: STL

Hmmm maybe ill see what what circle d says, but that sleeve is probably what i need.

Nov 10, 2013 | 06:30 AM

#13

Circle-D

FormerVendor

iTrader: (21)

Joined: Feb 2006

Posts: 2,474

Likes: 14

From: Houston, TX

You can run the crank spacer mrvedit suggested, but you will run it on the trans side of the flexplate. The spacer is designed to run with a flat flexplate on the 4L80 setup so you get the proper starter her engagement. But that has the 6 lug 11.5" bolt circle, so a no go for you. But there is a trick where you run the dished flexplate mounted to the crank and then bolt the spacer on the transmission side using it as a crank extender. And you will need to make sure the dished flexplate is a dual bolt pattern for your small GM bolt circle. Hope that made sense.

Chris

Nov 10, 2013 | 09:56 AM

#14

mrvedit

Moderator

Joined: Aug 2010

Posts: 7,323

Likes: 529

From: Ann Arbor, MI

The picture in Super Chevy Magazine shows the crank spacer on the trans side.

Nov 10, 2013 | 10:34 AM

#15

topgun542

Thread Starter

TECH Regular

iTrader: (6)

Joined: Apr 2010

Posts: 474

Likes: 2

From: STL

so will the flexplate on your website wont work? i just cant find any flexplates, except for 300+. hahaha so if im catching what your saying, i need a dished flex plate and run that spacer on the trans side?

Nov 10, 2013 | 11:11 AM

#16

Circle-D

FormerVendor

iTrader: (21)

Joined: Feb 2006

Posts: 2,474

Likes: 14

From: Houston, TX

Yes, our steel SFI option will work. It has the smaller 10.75" bolt circle you need. Then get the spacer and crank bolts mrvedit mentioned and you are good to go.

Chris