4L80s use a different hub than other transmissions to drive the pump. His is correct.

 

yea, 60e uses the tabs, 80e uses flat lands.

 

Have you witnessed that engine running? Did it come out of a wrecked truck?

I know you measured how far the converter is sitting in the trans, but try measuring how far the flexplate mounting holes are from the back of the block(use a strait-edge to measure from where the bellhousing bolts up). Something's not adding up...

 

On most LS engines the crank will stick out an average of 0.300" from the block. The Spacer and flexplate will add about 0.575", giving you a total distance of 0.875". With the converter to bell housing of 1.000-1.050, that gives you the .125-.175 of converter pull back/clearance.

Chris

 

Another tidbit of info... The curved flexplate averages about .550 in height, giving you about the same spacing as the 6.0 spacer and flat style. The differences are the bolt patterns and converter pilot length.

Chris

 

X2...where the flexplate bolts to the converter it should be the same distance as the 6.0L setup....just different on the pilot.

 

Not sure if this will help any,

Crankshaft Replacement Caution For
1998-2005 GM 4.3, 4.8, 5.3, 5.7 & 6.0L Engines

The AERA Technical Committee offers the following information on crankshaft replacement caution for 1998-2003 GM 4.3, 4.8, 5.3, 5.7 and 6.0L engines. Design changes in the flywheel flange thickness have been made to some crankshafts used in the above-mentioned engines. This bulletin is being re-published with additional information.

The later crankshafts are shorter on the flywheel flange as seen in the listing below. These changes are due to the many different vehicle / transmission combinations being built by GM.

A flywheel spacer ring GM Part #12563532 and a longer bolt set GM Part #12563533 is required when using a thin flange crankshaft to replace a thick flange crankshaft. Also, if the crankshaft is being used in a vehicle, which is a standard shift application, you also need pilot bushing GM Part #12557583 or 12479894.

Note: GM part numbers correct as of 12-18-04.

Years Liters Casting # Trans Flange Thickness

1998 early 4.3L 236, 255 V-6 1.62 thick flange
1998+up 4.3L 236, 255 V-6 1.500 thick flange
1999-2000 4.8L 312 V-8 M/T 1.250 thick flange
1999-2000 6.0L 215 V-8 1.250 thick flange
1999-2005 4.8L 482 V-8 A/T .857 thick flange
2001-2005 4.8L 482 V-8 M/T .857 thick flange
1999-2005 5.3L 216 V-8 A/T .857 thick flange
1997-2005 5.7L 216 V-8 .857 thick flange
2001-2005 6.0L 216 V-8 .857 thick flange

All GEN III crankshafts used in Camaro, Corvette and Firebird have a .857 thick flange and also have a freeze plug installed at the bottom of the pilot shaft hole. The 4.8, 5.3 + 6.0L don?t have the freeze plug. The drilled hole thru the centerline of the 5.7L LS1 & LS6 crankshafts allows a path to balance crankcase pressure within the lower crankcase. Doing so has eliminated possible oil consumption when the engine is operated over 4800 RPM.

Caution: Early crankshafts use a flat reluctor wheel and late have a recess. Recess will work on all years. Do not use a flat reluctor on late applications as it will cause an engine misfire.

Flexplate, spacer and bolts in a kit, only $64

LS Series Flexplate Kit 12621399 - Crate Engine Depot

peace
Hog

 

Thanks for input guys, take some of that dimension data and make a few more measurements off the engine when I get a chance. Got another 6L to do some comparison with.

 

Good info, thanks.... I will add it to our other findings.

Chris