Differences between early DMF and later DMF
Thread Starter
Racer
Joined: Sep 2008
Posts: 487
Likes: 4
Differences between early DMF and later DMF
For the L98, LT1 DMFs can you tell a visual difference between the early one, 89 and 90 (I think maybe 91 too), and later 92-96? Is there a casting difference or marking or something like that, or is it all internal? If it is internal what are the difference there and can you tell by rotation spec?
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
L98 and LT are 2 completely different animals.
L98 was TPI.
LT was multiport EFI. ID'd by no wrap around runner and the absence of a dist in the rear.LTs also came with intake covers.
L98 had a dist in back like all Gen-1 SBC and long tube runners. It is tall.
Gen 3,4,5 are just an evolution of the LT design. ABout as different as Cheeta is to Ahhhnold, but you get the obvious differences..
No parts can be interchanged. Not even plug wires...
L98 was TPI.
LT was multiport EFI. ID'd by no wrap around runner and the absence of a dist in the rear.LTs also came with intake covers.
L98 had a dist in back like all Gen-1 SBC and long tube runners. It is tall.
Gen 3,4,5 are just an evolution of the LT design. ABout as different as Cheeta is to Ahhhnold, but you get the obvious differences..
No parts can be interchanged. Not even plug wires...
Burning Brakes
Joined: Mar 2010
Posts: 1,094
Likes: 68
From: Providence RI
10085206 is the earlier part number which was superceded by 10174482 in late 89/early 90....maybe early 91? Dunno...
Both look virtually identical but there IS a build date stamped into the flywheel, i remember it being near the starter teeth on the non clutch side...I could be wrong on the location but there was indeed a build date in my DMF dated like 8/89 and it had the old part number stamped near where the flywheel to crank bolts go.
Hope this helps.
Mike
Both look virtually identical but there IS a build date stamped into the flywheel, i remember it being near the starter teeth on the non clutch side...I could be wrong on the location but there was indeed a build date in my DMF dated like 8/89 and it had the old part number stamped near where the flywheel to crank bolts go.
Hope this helps.
Mike
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Makes no difference
The flange on the crank is identical , auto vs man for a given year
The difference is between the early 2 pce RMS crank that has the large counterweight on the rear flange
and the later 1 pce RMS ('87+ L98 / LTX / Vortec) cranks that have a round flange and the balance weight is on the flexplate / flywheel
The PCD of the bolt pattern on the 1 pce cranks was changed to prevent inter-swapping of the flywheel / flexplate to the wrong engine
The flange on the crank is identical , auto vs man for a given year
The difference is between the early 2 pce RMS crank that has the large counterweight on the rear flange
and the later 1 pce RMS ('87+ L98 / LTX / Vortec) cranks that have a round flange and the balance weight is on the flexplate / flywheel
The PCD of the bolt pattern on the 1 pce cranks was changed to prevent inter-swapping of the flywheel / flexplate to the wrong engine
