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Mine's an "M" code


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"M" Codes! Absolute DO NOT SUCK!! The 1971 351C "M" code is the very best engine short of the Boss, which is basically the same, only a few tweaks and a few better parts.

The advertised compression ratio is 10.7:1 with Closed Chamber Quench heads at approx. 63cc volume. The valves are freakin huge, 2.19" inlet 1.71" exhaust

Earlier '70 heads are rated at 11:1 and 62cc volume. These are D0AE-N. Mine are D0AE-GA which are a bit later, cast in Dec 1970.

Deck height is .028" with a .039" compressed head gasket.

What you are reading is a lot of the members own 72 or 73 cars. The 4V was called a "Q" code, but the compression ratio was on a downslide from early 72 to the end in 73. The "H" code was the 2V engine.  The "J" or "C" code was the 429.

DO NOT mistake the 74 351M engine. These are NOT the same at all and are a POS! Truck motors!!

Hope that clears up what you have. Very easy to do research on the web, but be cautious, lots of misleading stuff out there.

www.Mustangtek.com is good for researching casting numbers. also www.351C.net (another forum), very useful, but...…..

ENJOY your "M" code!!

Geoff

 

 

IMG-0657-3.jpg

Geoff.

 I learn something new every day!

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"M" code is good. Plenty of power stock, doesn't take much to bump up the horsepower. If you want a lot of power, easy to stroke it to 408 cubic inches.

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

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"M" code is good. Plenty of power stock, doesn't take much to bump up the horsepower. If you want a lot of power, easy to stroke it to 408 cubic inches.

+1

408 strokers with 4v heads (M408) can produce monster power.

 

Sent from my SAMSUNG-SM-G930A using Tapatalk

20160929_171923_edit2_small.jpg

 

1971 M-Code Mach 1 w/Ram Air, 408 stroker, 285/291 0.558" roller cam, Blue Thunder intake, TKO600, Hooker headers with electric cut-offs, FiTech EFI w/ RobBMC PowerSurge pump

Strange center section with Truetrac, 3.5 gear and 31 spline axles, 4-wheel disc brakes

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M code is fine for sure. Is your car a sportsroof? Maybe with the chrome rocker trim.

Welcome to the forum from N.C..

 

 If you were not aware, David is referring to a car with a VIN of (for a 71) 1f02M XXXXXX i.e. sportroof. The Boss would be 1f02RXXXXXX The Mach 1 would be 1f05MXXXXXX. which is probably what you have. In this case "f" means it was built in Deardorn. If it's a "t" it was built in Metuchen. 02 =Sportroof, 05= Mach1,

If you don't yet have one, you can get a "Marti Report" from www.martiauto.com It will tell you all about YOUR car.

Geoff.

Geoff.

 I learn something new every day!

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71-72 CJ was a better performance package than the M code. Ford made lots of mistakes with the 70-71 M-code drivetrain setups and fixed it in May of 71 with the Q code.

 

 Not here to argue and maybe I'm biased. Perhaps the early 72's were a bit better for performance, but from the all accounts, it was a downhill slide from there on.

 With timing changes, a bit better cam and a decent carb, an M code will run with the best. That's my 2 cents worth.

Geoff.

 I learn something new every day!

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71-72 CJ was a better performance package than the M code. Ford made lots of mistakes with the 70-71 M-code drivetrain setups and fixed it in May of 71 with the Q code.

 

 Not here to argue and maybe I'm biased. Perhaps the early 72's were a bit better for performance, but from the all accounts, it was a downhill slide from there on.

 With timing changes, a bit better cam and a decent carb, an M code will run with the best. That's my 2 cents worth.

 

Not arguing, we're having a discussion. Notice my use of "package", which encompasses the engine, transmission and rear axle. Ford treated the M-code like a 351W, with a small carb, tiny camshaft, tight converter and the availability of 3.00 gears, which were all wrong for this engine. However, it did well considering the drivetrain configuration straight from the station wagon parts bin. 

 

I'd surmise that the Q-code was the result of what Ford learned with the Boss 351 program mixed with the 429 going away and the reality of the EPA regs coming down the pike in '72. They had to do something to keep the performance image. The CJ cam is about as perfect a well-mannered street cam as they come, coupled with a slippy converter on the C-6 cars and appropriate gearing really helped out off the line.

 

 

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71-72 CJ was a better performance package than the M code. Ford made lots of mistakes with the 70-71 M-code drivetrain setups and fixed it in May of 71 with the Q code.

 

 Not here to argue and maybe I'm biased. Perhaps the early 72's were a bit better for performance, but from the all accounts, it was a downhill slide from there on.

 With timing changes, a bit better cam and a decent carb, an M code will run with the best. That's my 2 cents worth.

 

Not arguing, we're having a discussion. Notice my use of "package", which encompasses the engine, transmission and rear axle. Ford treated the M-code like a 351W, with a small carb, tiny camshaft, tight converter and the availability of 3.00 gears, which were all wrong for this engine. However, it did well considering the drivetrain configuration straight from the station wagon parts bin. 

 

I'd surmise that the Q-code was the result of what Ford learned with the Boss 351 program mixed with the 429 going away and the reality of the EPA regs coming down the pike in '72. They had to do something to keep the performance image. The CJ cam is about as perfect a well-mannered street cam as they come, coupled with a slippy converter on the C-6 cars and appropriate gearing really helped out off the line.

 Hemikiller,

That is excellent information on the total drive train. I had not considered all those factors in the discussion and you're right, no-one is arguing.

 As a 4 speed owner of both an M code and in the past, an early 72 Q code, the automatic transmission set-up is not familiar. I will say I wish the "M" had come with at least a 3.50:1 trac-lok rear end instead of a 3.25:1 open. The car, even with the small engine upgrades that have been done, is still a dog off the line. I could change that, but I chose to leave it as is for now. We pay a lot more for gas here than in the States and our friend in the UK pays way more than both of us. Mileage counts!

Geoff.

 I learn something new every day!

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I guess I'm lucky, when I bought mine it already had a Shelby (Blue Thunder) intake, Shelby hydraulic cam, 3.73 gears with Detroit locker, and 760cfm Holley. The only thing that it didn't have was a better torque converter. So, mine was a pleasure to stomp on the pedal :)

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

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