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    Fuzzy match across codes, option descriptions, and model aliases. Every result is graded and, where the factory documents it, cited.

    Source document

    docs/rpo/buick/roadmaster-b-body.md

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    Rendered verbatim from the reference. Factory citations shown as ⛭ GM Heritage — …. For filtering, badges, and crosslinks, use the interactive Roadmaster — B-body (1991–1996) page.

    Buick Roadmaster — B-body (one generation) (1991–1996)

    The 1991–1996 Roadmaster was Buick's rear-drive B-body car: Wikipedia gives the Estate Wagon alone for 1991 and adds a four-door sedan for 1992, and the 1992 and 1996 NICB manuals list the Roadmaster, Roadmaster Estate Wagon and Roadmaster Limited car lines. Wikipedia gives the 5.0L L03 V8 to the 1991 wagon, the 5.7L L05 V8 to the 1992–1993 cars and the 5.7L LT1 V8 from 1994, with the hydraulic 4L60 four-speed automatic replaced by the electronically controlled 4L60-E for 1994. No GM order guide, data book, Heritage kit or RPO list for the Roadmaster is in the archive, so only engine and transmission codes are listed: they come from Wikipedia's Roadmaster and 4L60-E articles and, for the codes the B-body cars share, the Chevrolet Caprice kits (order-guide power teams and MVMA specification pages with a printed model year), with Wikipedia's Oldsmobile Custom Cruiser article (the 1991–1992 B-body wagon) named where it agrees. The options, the towing package Wikipedia describes, the dual exhaust, paint and trim are a gap in the sources, not a finding that they were not offered.

    Codes

    Engines

    Code Description Years Models/Notes Confidence
    L03 Engine, 5.0L V8, electronic fuel injection 1991 170 hp; the standard engine of the 1991 car, the Estate Wagon only; Wikipedia's Roadmaster article names L03 and dates it 1991; shared B-body code; Wikipedia's Oldsmobile Custom Cruiser article (the B-body wagon sibling) also names the L03 and dates the 5.0L 1991, but as a second Wikipedia article it is not counted as an independent source; the Chevrolet Caprice kit's 1991 specification pages (pp.6 and 45) print LO3 but no readable model year (the p.45 year field prints only the issue date 12-89), so they date no year and are not cited single-source
    L05 Engine, 5.7L V8, electronic fuel injection 1992–1993 180 hp, sedan and wagon; Wikipedia's Roadmaster article names L05 as the L03's replacement for 1992, until the LT1 of 1994; Wikipedia's Oldsmobile Custom Cruiser article (the B-body wagon sibling) dates the L05 1992; shared B-body code; cited from the Chevrolet Caprice kit: the MVMA specification pages for model years 1992 (power team D, printed LO5, the police 9C1 sedan, and the police-sedan engine page) and 1993 (power teams, LO5), and the 1993 order-guide power teams; 1993 p.22's fourth column prints LOS (an S for the 5), which is not read ⛭ GM Heritage — 1992 Chevrolet Caprice, p.6 ⛭ GM Heritage — 1992 Chevrolet Caprice, p.8 ⛭ GM Heritage — 1993 Chevrolet Caprice, p.10 ⛭ GM Heritage — 1993 Chevrolet Caprice, p.22 confirmed
    LT1 Engine, 5.7L V8, sequential fuel injection 1994–1996 260 hp, sedan and wagon; Wikipedia's Roadmaster article names LT1 from 1994 and its OBD-II change for 1996; shared B-body code; cited from the Chevrolet Caprice kit ⛭ GM Heritage — 1994 Chevrolet Caprice, p.12 ⛭ GM Heritage — 1995 Chevrolet Caprice, p.7 ⛭ GM Heritage — 1996 Chevrolet Caprice, p.11 confirmed

    Transmissions

    Code Description Years Models/Notes Confidence
    MD8 Transmission, 4 speed automatic, 4L60 1991–1993 the hydraulically controlled 4L60 (700R4) behind every engine, replaced for 1994 (Wikipedia's Roadmaster article, which prints no code); the code is from Wikipedia's 4L60-E article, which names the 4L60 as RPO MD8; shared B-body code; cited from the Chevrolet Caprice kit, whose MVMA specification power teams print MD8 for model years 1992 and 1993; 1991 rests on Wikipedia alone, because the kit's 1991 power-team page (p.45) prints MD8 with no readable model year, so the row is single-source; GM's later lists reuse MD8 for a 4L70-E ⛭ GM Heritage — 1992 Chevrolet Caprice, p.6 ⛭ GM Heritage — 1993 Chevrolet Caprice, p.22 single-source
    M30 Transmission, 4 speed automatic 1994–1996 the electronically controlled 4L60-E; Wikipedia's 4L60-E article names it RPO M30 and lists the Roadmaster for 1994–1996, which dates every year; shared B-body code; cited from the Chevrolet Caprice kit's MVMA specification pages for model years 1994 (the LT1 engine page), 1995 and 1996 (power teams, M30 with the LT1); the 1994 pages whose year field reads '•394' or '*394' (pp.37, 57) are not cited ⛭ GM Heritage — 1994 Chevrolet Caprice, p.38 ⛭ GM Heritage — 1995 Chevrolet Caprice, p.18 ⛭ GM Heritage — 1996 Chevrolet Caprice, p.22 confirmed
    MX0 Transmission, 4 speed automatic, overdrive 1993–1996 the order code the Caprice order guides print for the four-speed automatic, matched to the Roadmaster's unit by meaning: no Roadmaster source prints MX0; the pages print MXO; the 1993 order guide prints MXO for the power teams the 1993 specification page codes MD8, and the 1994–1996 guides for those the specification pages code M30, the pages not saying whether the codes are one unit; 1991–1992 are left out because no kit page with a printed model year prints it (the 1991 specification page prints MXO and no model year); shared B-body code; cited from the Chevrolet Caprice kit ⛭ GM Heritage — 1993 Chevrolet Caprice, p.10 ⛭ GM Heritage — 1994 Chevrolet Caprice, p.12 ⛭ GM Heritage — 1995 Chevrolet Caprice, p.8 ⛭ GM Heritage — 1996 Chevrolet Caprice, p.12 single-source

    Sources

    Factory documents (T1)

    No Buick factory document for the 1991–1996 Roadmaster is in docs/factory-docs/ or docs/heritage-ocr/. The rows cite the Chevrolet Caprice Heritage kits (B-body twins) for shared engine and transmission codes only, on the brief's listed RPO pages and the extra pages the owner allowed (2026-11-05):

    • [HK] chevrolet/1992-Chevrolet-Caprice.txt — MVMA specifications, model year 1992: Caprice sedan power teams (p. 6) and the police sedan's L05 engine page (p. 8)
    • [HK] chevrolet/1993-Chevrolet-Caprice.txt — 1993 order guide, Caprice Classic LTZ colour, trim and power teams (p. 10); MVMA specifications, model year 1993, power teams (p. 22)
    • [HK] chevrolet/1994-Chevrolet-Caprice.txt — 1994 order guide power teams (p. 12); MVMA specifications, model year 1994: the LT1 engine page (p. 38)
    • [HK] chevrolet/1995-Chevrolet-Caprice.txt — 1995 order guide option page (p. 7) and power teams (p. 8); MVMA specifications, model year 1995, power teams (p. 18)
    • [HK] chevrolet/1996-Chevrolet-Caprice.txt — 1996 order guide option page (p. 11) and power teams (p. 12); MVMA specifications, model year 1996, power teams (p. 22)

    Other sources

    • https://en.wikipedia.org/wiki/Buick_Roadmaster — 1991–1996 section: body styles by year, engines (L03, L05, LT1) and transmissions (4L60, 4L60-E) by year, standard dual exhaust, the towing package, assembly plants and the production table (retrieved 2026-11-05 as wikitext, action=raw)
    • https://en.wikipedia.org/wiki/GM_4L60-E_transmission — the 4L60 as RPO MD8, the 4L60-E as RPO M30, and the Roadmaster among the 4L60-E applications for 1994–1996 (retrieved 2026-11-05 as wikitext, action=raw)
    • https://en.wikipedia.org/wiki/Oldsmobile_Custom_Cruiser — the 1991–1992 B-body wagon sibling: L03 for 1991, L05 added for 1992, the 4L60 four-speed automatic (retrieved 2026-11-05 as wikitext, action=raw)
    • NICB Passenger Vehicle Identification Manual, GM sections (T4): docs/reference/nicb/nicb1991-gm.txt p.35, nicb1992-gm.txt p.38 and nicb1996-gm.txt p.37, read on the page images — Roadmaster car lines (BN Roadmaster, BR Roadmaster Estate Wagon, BT Roadmaster Limited; the 1991 manual names the BR line LeSabre Estate Wagon)