What was the quarter mile time for mid-size 1970 Mopars with a 198 cubic inch Slant Six engine
Executive summary
There is no authoritative, factory or magazine-sourced quarter‑mile time for a stock mid‑size 1970 Mopar fitted with the 198 cubic‑inch Slant Six in the reporting provided; sources document the engine changeover, displacement and power ratings, and anecdotal/modified‑engine quarter‑mile results but do not record a verified stock quarter‑mile number [1] [2] [3]. Published performance claims in the supplied material are either general engine specs (power/torque and model fitment) or forum anecdotes about heavily modified Slant Sixes — meaning any exact quarter‑mile figure for a stock 1970 mid‑size Mopar with the 198 must be treated as an estimate absent primary test data in these sources [2] [3].
1. The question being asked and what the sources actually cover
The user seeks a specific quarter‑mile time for mid‑size 1970 Mopars equipped with the 198 ci Slant Six; the documents collected describe the 198’s introduction and mechanical details, list which cars carried it, and record factory horsepower/torque claims, but none of the supplied items present an authoritative factory or contemporary road‑test quarter‑mile time for a stock 1970 mid‑size Mopar with the 198 engine [1] [4] [2]. Forum threads and enthusiast writeups in the packet discuss swaps, stroking, and extreme race builds that post very different elapsed times — useful for context, not for establishing stock performance [3].
2. What the reporting says about the 198 Slant Six’s output and fitment
Contemporary and retrospective sources make clear Chrysler replaced the 170 with the 198 in 1970 and that the 198 shared the taller block with the 225 while using a shorter stroke and longer rods; publications list the 198 as the base six for many small and pony Mopars of that year [1] [5] [6]. Popular summaries attribute roughly 125 hp and about 180 lb‑ft for early 1970s 198 Slant Six ratings in passenger cars such as the Valiant and base Challengers/Barracudas, which frames realistic expectations for acceleration from factory trim [2].
3. Why exact quarter‑mile figures are absent in these sources
The supplied corpus is heavy on technical history, enthusiast commentary, and aftermarket tales but lacks contemporaneous road‑test tables or dragstrip result compilations for stock 1970 mid‑size Mopars with the 198 — magazines and test sheets that normally publish quarter‑mile ETs are not among the documents provided [1] [2] [7]. That gap is consequential: without an original test result, any numerical ET must either be sourced from an uncited owner’s claim or modeled from power, gearing and weight assumptions not present in these citations.
4. What the reporting does show about extreme and modified Slant Six performance
Enthusiast forums and build writeups in the corpus show the Slant Six platform can be radically transformed: a stroked and overbored Slant Six built for racing produced quarter‑mile times in the low 11‑second range (an example cited is a 10.87s pass with a stroked/overbored 242‑ci Slant in a forum thread), but those are explicitly all‑out racing builds requiring extensive, non‑stock work and therefore are not indicative of factory 198 performance [3]. This demonstrates the gap between stock spec and heavily modified outcomes and underscores the risk of conflating forum bragging with OEM test data.
5. A reasoned estimate and the limits of that estimate
Given the documented factory power rating for the 198 Slant Six in 1970 passenger applications (about 125 hp) and the fact that mid‑size Mopar bodies of the era were not lightweight, a plausible, cautious estimate for a stock mid‑size 1970 Mopar with the 198 (manual or automatic depending on gearing) would put quarter‑mile ETs well slower than high‑performance V8s of 1970 — commonly in the mid‑ to high‑teens seconds to low‑18s range — but this is an engineering inference, not a sourced fact from the provided materials and should be treated as an estimate only. The sources supplied do not contain measured ETs for stock cars, so this remains a reasoned approximation rather than a documented claim [2] [1].
6. Alternatives, agendas, and where to look next
Enthusiast forums and retrospective sites can amplify remarkable race builds or selective memories and thus skew perceptions; the forum example of a 10.87s Slant Six run illustrates how extreme modifications, not factory state, can dominate online narratives [3]. For definitive stock quarter‑mile numbers, primary period road‑tests or dragstrip result archives (magazines like Car and Driver, Motor Trend, Hot Rod from 1970) or factory test sheets would be required — those sources were not included in the reporting provided and are the logical next stop for anyone seeking a documented ET.