1978 Pace Car production question!
06-01-2005, 04:11 PM
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1978 Pace Car production question!
Out of the 6502 pace cars produced in 1978, does anyone know how many were ordered with the L82/4 speed manual combination? Thanks in advance!
06-01-2005, 05:37 PM
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Doesn't break down like that.
There were 12,739 L82's, 3,385 4spd's and 6,502 Pace cars
How many Pace cars had this combination is unknown.
There were 12,739 L82's, 3,385 4spd's and 6,502 Pace cars
How many Pace cars had this combination is unknown.
Last edited by gq82; 06-01-2005 at 05:40 PM.
06-01-2005, 06:35 PM
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Keep in mind there were also some 4500+ M20 4speeds that weren't counted as options. Standard equipment. If you didn't specify the M21 or the automatic on the option sheet you got the M20 Wide ratio 4 speed. Also, the M21 was not available with the L48.
Mike
Mike
06-01-2005, 10:09 PM
#6
Originally Posted by KapsSA
Keep in mind there were also some 4500+ M20 4speeds that weren't counted as options. Standard equipment. If you didn't specify the M21 or the automatic on the option sheet you got the M20 Wide ratio 4 speed. Also, the M21 was not available with the L48.
Mike
Mike
But why do all references on this subject say 3385 manual transmissions were sold ???? Also,I've read where less than 10% were sold with manual tranny's in 78 ???
Last edited by rihwoods; 06-01-2005 at 10:28 PM.
06-01-2005, 11:34 PM
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MM4 is the "standard" 4 speed, commonly called the M20. Wide ratio. Available with both the L82 or the L48 but the only one available with the L48.
If you add up the numbers in the Corvette Black Book, you get 46776 total 78 production including Pace Cars. M21 4speed and MX1(Or M38 on my 3 build sheets, MX1 on the window stickers) automatics total up to 41999 units. Leaves 4778 unaccounted for.
Also in the Black Book, it states:"A 350ci. 185hp-engine, 4-speed wide ratio manual transmission, T-tops, and leather interior trim were included in the base price". Pretty much states that info for several C3 years.
I read this somewhere else also but for the life of me I don't remember where!
If you go back in the Black Book and look at other years you also see the same disparity of numbers.
Hopefully someone else can add some more info.
Mike
If you add up the numbers in the Corvette Black Book, you get 46776 total 78 production including Pace Cars. M21 4speed and MX1(Or M38 on my 3 build sheets, MX1 on the window stickers) automatics total up to 41999 units. Leaves 4778 unaccounted for.
Also in the Black Book, it states:"A 350ci. 185hp-engine, 4-speed wide ratio manual transmission, T-tops, and leather interior trim were included in the base price". Pretty much states that info for several C3 years.
I read this somewhere else also but for the life of me I don't remember where!
If you go back in the Black Book and look at other years you also see the same disparity of numbers.
Hopefully someone else can add some more info.
Mike
Thats the number I have always heard. I guess I am one of the lucky ones!
06-02-2005, 12:20 AM
#9
Originally Posted by KapsSA
MM4 is the "standard" 4 speed, commonly called the M20. Wide ratio. Available with both the L82 or the L48 but the only one available with the L48.
If you add up the numbers in the Corvette Black Book, you get 46776 total 78 production including Pace Cars. M21 4speed and MX1(Or M38 on my 3 build sheets, MX1 on the window stickers) automatics total up to 41999 units. Leaves 4778 unaccounted for.
Also in the Black Book, it states:"A 350ci. 185hp-engine, 4-speed wide ratio manual transmission, T-tops, and leather interior trim were included in the base price". Pretty much states that info for several C3 years.
I read this somewhere else also but for the life of me I don't remember where!
If you go back in the Black Book and look at other years you also see the same disparity of numbers.
Hopefully someone else can add some more info.
Mike
If you add up the numbers in the Corvette Black Book, you get 46776 total 78 production including Pace Cars. M21 4speed and MX1(Or M38 on my 3 build sheets, MX1 on the window stickers) automatics total up to 41999 units. Leaves 4778 unaccounted for.
Also in the Black Book, it states:"A 350ci. 185hp-engine, 4-speed wide ratio manual transmission, T-tops, and leather interior trim were included in the base price". Pretty much states that info for several C3 years.
I read this somewhere else also but for the life of me I don't remember where!
If you go back in the Black Book and look at other years you also see the same disparity of numbers.
Hopefully someone else can add some more info.
Mike
Good catch,KapsSA.....
Last edited by rihwoods; 06-02-2005 at 12:22 AM.
06-02-2005, 01:07 AM
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I did some research years ago for my black 79, same disparity in 4speed numbers, but more like 8000 unaccounted for. Same standard vs. option thing. I've had this Vette 21 years.
Mike
I've also heard the 220 Pace Car 4speed stat. also.
06-02-2005, 05:34 AM
#11
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Originally Posted by KapsSA
MM4 is the "standard" 4 speed, commonly called the M20. Wide ratio. Available with both the L82 or the L48 but the only one available with the L48.
If you add up the numbers in the Corvette Black Book, you get 46776 total 78 production including Pace Cars. M21 4speed and MX1(Or M38 on my 3 build sheets, MX1 on the window stickers) automatics total up to 41999 units. Leaves 4778 unaccounted for.
Also in the Black Book, it states:"A 350ci. 185hp-engine, 4-speed wide ratio manual transmission, T-tops, and leather interior trim were included in the base price". Pretty much states that info for several C3 years.
I read this somewhere else also but for the life of me I don't remember where!
If you go back in the Black Book and look at other years you also see the same disparity of numbers.
Hopefully someone else can add some more info.
Mike
If you add up the numbers in the Corvette Black Book, you get 46776 total 78 production including Pace Cars. M21 4speed and MX1(Or M38 on my 3 build sheets, MX1 on the window stickers) automatics total up to 41999 units. Leaves 4778 unaccounted for.
Also in the Black Book, it states:"A 350ci. 185hp-engine, 4-speed wide ratio manual transmission, T-tops, and leather interior trim were included in the base price". Pretty much states that info for several C3 years.
I read this somewhere else also but for the life of me I don't remember where!
If you go back in the Black Book and look at other years you also see the same disparity of numbers.
Hopefully someone else can add some more info.
Mike
1. Colvin's "Corvette by the Numbers 55-82" (a great resource)
2. GM's Chevrolet 1978 Corvette Specifications
3. Other research resources.
Colvin points out that GM was always interested in saving $ so the M20 was base and the least expensive option (not unlike the transition from M40 to M38 in 76). The higher gear ratio offered "more punch" to the measley 185 hp L48 and helped meet EPA emission standards. Also note...no 4 speeds permitted for CA bound Corvettes! After 1980 the M20 was gone and the Borg Warner 4 speed was used for 80-81 (MM4)...and than it was gone as well. GM could not meet the emission standards with a manual transmission...electronic fuel control was not sufficiently developed to compensate for the range of driving experiences the 4 speed offered the sport enthusiast driver.
I looked through all my build sheets...but not a one calls out the MM4 (or M20 wide ratio tranny) which really doesn't mean anything. What we need here is to see a build sheet for a base L48 with no automatic specified (L48 M20) to learn what was called out on the build sheet. I suspect the MM4 as Kaps indicates is on the invoice. But than MX1 was referenced in Black Book, printed on the window sticker and M38 printed on build sheets. I have a set of documents that demonstrates this anomaly (consistent with kaps and one of my sources).
Finally, when M20 was installed with L82, power team charts show a ratio in-between both the M20 L48 (2.85:1) and the M21 L82 (2.43:1). Charts show a ratio of 2.64:1 and I'm not sure if the gears were modified when L82 was specified or if this was accomplished by equipping the power team with the 3.70:1 rear end axle. The 3.36 rear end was base with the L48 M20 while 3.70 was base when L82 M21 was specified. Looks like when L82 M20 was ordered...buyer had an option but I'm not able to confirm. Colvin shows a footnote that all B/W tranny's had an additional 2-digit code on the maincase, below the sidecover to identify the first gear ratio:
HS=2.64:1; HW=2.43:1
So what I'm concluding here is that there were three four-speed transmissions offered in 78-79. Base L48 unit was the Muncie M20; L82 base transmission was B/W M20 with 2:64:1 ratio and the L82 heavy-duty M21 B/W with 2.43:1 ratio. I believe the RPO for the L48 base M20 was the MM4 while the M20 RPO was the L82 base 4-speed. And of course heavy-duty L82 for the M21 RPO.
Of course I could be way off here but you guys will help to enlighten us. So we need all you 78-79 4-speed guys to check your codes!
Last edited by hunt4cleanair; 06-02-2005 at 05:36 AM.
06-02-2005, 09:22 AM
#12
Drifting
From the specifications sent to me in the restoration package one used to be able to get (maybe still can) these are the MVMA specs produced by GM
On the L-82:
Either 4 speed came standard with the 3.70:1 rear except for high altitude option G95 on the M20 (for altitudes of 4000 feet or higher) which was a 3.36:1
The L-48 m20 came with a 3.36:1 rear ratio while the MX1- th350 came with a 3.08:1 rear ratio - except in CA (3.55:1) or high altitude 3.55:1 (outside CA)
The L-82 was not available in California, Maryland, Florida, Oregon, and Washington States; Boston, Mass; Grand Rapids, Mich.; and DesPlaines, Barrington and Cook counties, Illinois
I show the same number discrepancies as everyone else...wonder why they always seem to float around as no two sources seem to have the exact same numbers..
I would agree
Code:
MM4(M20)for L-48 MM4(M20)for L-82 M-21 ( L-82 only) 1st gear 2.85 2.64 2.43 2nd gear 2.02 1.75 1.61 3rd gear 1.35 1.34 1.23 4th gear 1.00 1.00 1.00 reverse 2.85 2.55 2.35
Either 4 speed came standard with the 3.70:1 rear except for high altitude option G95 on the M20 (for altitudes of 4000 feet or higher) which was a 3.36:1
The L-48 m20 came with a 3.36:1 rear ratio while the MX1- th350 came with a 3.08:1 rear ratio - except in CA (3.55:1) or high altitude 3.55:1 (outside CA)
The L-82 was not available in California, Maryland, Florida, Oregon, and Washington States; Boston, Mass; Grand Rapids, Mich.; and DesPlaines, Barrington and Cook counties, Illinois
I show the same number discrepancies as everyone else...wonder why they always seem to float around as no two sources seem to have the exact same numbers..
So what I'm concluding here is that there were three four-speed transmissions offered in 78-79.
06-02-2005, 11:02 AM
#13
I have a 78 L-82 3.70:1 rear and my copy of the dealer invoice states:"8YMM4 Four Speed Manual Transmission"
I have not found the build sheet, yet. So I assume it is the 2.64 version. I think also I remember seeing HS on the tranny,so must confirm that...
I have not found the build sheet, yet. So I assume it is the 2.64 version. I think also I remember seeing HS on the tranny,so must confirm that...
06-02-2005, 11:09 AM
#14
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Several places in the Corvette Restoration Package lit. it states the M21 as n/a with the L48. Also, again from the Black Book, at least for both 77 and 79 (ran out of print space for 78?) that the M21 close ratio was a no cost option but required L82. I also see 2 different geared M20s(2.85 and 2.65 low)listed in the "Package" for a total of 3 4speeds.
Later, Mike
Later, Mike
Last edited by KapsSA; 06-02-2005 at 11:13 AM.
06-02-2005, 11:44 AM
#15
Melting Slicks
Here's my take...M21 4-spd, Close Ratio Manual Transmission 3,385
MM4 4-spd, Wide Ratio Manual Transmission 4,773
I know I have a '78 L82 M21 3:70...for what's it's worth...
MM4 4-spd, Wide Ratio Manual Transmission 4,773
I know I have a '78 L82 M21 3:70...for what's it's worth...
06-02-2005, 11:47 AM
#16
Originally Posted by KapsSA
Several places in the Corvette Restoration Package lit. it states the M21 as n/a with the L48. Also, again from the Black Book, at least for both 77 and 79 (ran out of print space for 78?) that the M21 close ratio was a no cost option but required L82. I also see 2 different geared M20s(2.85 and 2.65 low)listed in the "Package" for a total of 3 4speeds.
Later, Mike
Later, Mike
Rich
06-02-2005, 11:55 AM
#17
Originally Posted by mvftw
Here's my take...M21 4-spd, Close Ratio Manual Transmission 3,385
MM4 4-spd, Wide Ratio Manual Transmission 4,773
I know I have a '78 L82 M21 3:70...for what's it's worth...
MM4 4-spd, Wide Ratio Manual Transmission 4,773
I know I have a '78 L82 M21 3:70...for what's it's worth...
06-02-2005, 04:49 PM
#18
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Originally Posted by rihwoods
What numbers/letters exist on your tranny? I'm getting mine tomorrow as I have missed placed my notes from months ago...think I remember seeing "HS",but can't recall exactly...I will post whatever it is...
06-02-2005, 05:12 PM
#19
Originally Posted by hunt4cleanair
Colvin states they are painted...so if so...get some pics.
Speaking "paint" markings,found this on lower driver fender well below booster....alarm horn...
Part number? Inspection? numbers are 6 27 2.
06-02-2005, 06:33 PM
#20
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OK, to run off on yet another sidetrack, Tom, do you have any build sheets for L48 automatics? Is it specified as MX1 or M38? I'm thinking the "popular" code of MX1 was on the window stickers but for the L82 equipted automatics the build sheet says M38 to specify the slightly "tweaked" auto that went into the higher performance Vettes. Of course if the L48 build sheet says M38 I'm still confused!! 
Also, does anyone have an L48 4speed window sticker to see if the trans is even listed in the options column?
Mike
Also, does anyone have an L48 4speed window sticker to see if the trans is even listed in the options column?
Mike
