Buick Roadmaster LT1
10-11-2010, 09:00 AM
#1
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Buick Roadmaster LT1 I found an LT1 for my 85 TA. The guy says it's out of a 94 Roadmaster and it comes with the full long block, all the accessories, the harness, the pcm, and the trans. So my question is, is there a difference between an LT1 from an f-body and an LT1 from a Roadmaster? If so, what are the differences? I thought I heard somewhere that if it wasn't from an f-body or a vette, then it probably has iron heads instead of aluminum. Also, should I use one from a Roadmaster or other non-sports car, or should I try to find one out of an f-body or a vette? Thanks guys!
10-11-2010, 09:37 AM
#2
You first need to establish whether or not you have an LT1 or an L99. L99s are externally identical to LT1s with the exception of a few distinguishing marks. At the back of the block where it meets the intake manifold it will say either 5.7 or 4.3. If it says 4.3, stay away. 
10-11-2010, 09:43 AM
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You first need to establish whether or not you have an LT1 or an L99. L99s are externally identical to LT1s with the exception of a few distinguishing marks. At the back of the block where it meets the intake manifold it will say either 5.7 or 4.3. If it says 4.3, stay away.
10-11-2010, 09:47 AM
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You first need to establish whether or not you have an LT1 or an L99. L99s are externally identical to LT1s with the exception of a few distinguishing marks. At the back of the block where it meets the intake manifold it will say either 5.7 or 4.3. If it says 4.3, stay away.
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10-11-2010, 10:16 AM
#8
The official "Gen IV" engine was released in 2005 as the LS2+ series. We're talking about an old Fleetwood.
Here's what I understand:
Gen I = SBC beginning in 1955 until 1991
Gen II = LT1, 1992 - 1997
Gen III = LS1, 1997 - 2004
Gen IV = LS2+, 2005+
You have me curious on what you're talking about.
Here's what I understand:
Gen I = SBC beginning in 1955 until 1991
Gen II = LT1, 1992 - 1997
Gen III = LS1, 1997 - 2004
Gen IV = LS2+, 2005+
You have me curious on what you're talking about.
10-11-2010, 01:27 PM
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The official "Gen IV" engine was released in 2005 as the LS2+ series. We're talking about an old Fleetwood.
Here's what I understand:
Gen I = SBC beginning in 1955 until 1991
Gen II = LT1, 1992 - 1997
Gen III = LS1, 1997 - 2004
Gen IV = LS2+, 2005+
You have me curious on what you're talking about.
Here's what I understand:
Gen I = SBC beginning in 1955 until 1991
Gen II = LT1, 1992 - 1997
Gen III = LS1, 1997 - 2004
Gen IV = LS2+, 2005+
You have me curious on what you're talking about.
10-11-2010, 05:39 PM
#14
The shortblock is the same as a f-body, the heads and cam are different but both are probably going to be changed if you are looking for performance.
It will have the later vented opti as the b-bodies got that in 94 with the introduction of the LT1.
As was covered the 94-96 Roadmasters, Fleetwoods and wagons(Caprice or Roadmaster) all got the LT1 standard. Guys here like to worry a LOT about the L99 BUT it was the base engine in the Caprice sedan only from 94-96, LT1 was optional for civilian or police cars and standard with the Impala SS TRIM PACKAGE.
Honestly when buying a 15yo motor I would probably rather have the b-body one because it is more likely well cared for than a beat on f-body or Vette one.
It will have the later vented opti as the b-bodies got that in 94 with the introduction of the LT1.
As was covered the 94-96 Roadmasters, Fleetwoods and wagons(Caprice or Roadmaster) all got the LT1 standard. Guys here like to worry a LOT about the L99 BUT it was the base engine in the Caprice sedan only from 94-96, LT1 was optional for civilian or police cars and standard with the Impala SS TRIM PACKAGE.
Honestly when buying a 15yo motor I would probably rather have the b-body one because it is more likely well cared for than a beat on f-body or Vette one.
10-11-2010, 05:56 PM
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I used a lt1 from a 95 impala ss to put in my 85 TA. The under hood fuse box makes it really simple to do the swap. Pick up some gauges from a 86-92 car so you can use the elec. 145mph speedo instead of the mech. 85mph gauge that you have now. A little re-pinning of the harness but not that hard to do. try lt1swap.com for some wiring diagrams of the harness.
10-11-2010, 06:42 PM
#16
early/mid 90's L99= 4.3L V8 found in some b-body cars
Modern L99=6.2L 400hp V8 in the automatic 2010-present Camaro SS's.
The L99's offered in the 90's are in fact nearly identical to the 5.7 LT1's, all the above info is correct about them. They are not in reference to the modern 6.2L.
