Jump to content

1971 Convertible - 351C 4V M-code


tuomo
 Share

Recommended Posts

Hello

 

I am new to the forum, however have had a 1971 Convertible for a few years now. It has a 351C 4v M-code, C-6, Grabber Yellow, Factory Air, PW, PS, Power Disks , Deluxe Interior - so pretty much the whole bag of tricks for this years Mustang. . The car was a special order car from what I know and was handed down to me a few years ago making me the 2nd owner after my grandfather.

 

I have started restoring it while keeping it driveable. The Marti report tells me this is a relatively unique car so I am not going to do any visible customization = trying to keep it as original as much as possible.

 

My next quest is have the engine rebuilt and enhanced. It's got 136k miles on it but runs pretty strong and is relatively clean. I have talked to a few machine shops in my area ( Northern Virginia ) and read a lot of posts here and at 351Cleveland.net as well as some other Ford forums. Here's my thinking on the engine:

 

- Stroke it to a 393 ( vs. anything else ? )

- Keep the closed chamber 4V heads. Someone told me to swap in aluminum heads but I don't see a reason other than weight. Also I believe the original heads maintain the originality and value of the car.

- Currently has a Holley 4-barrel 650 CFM . Keep that until I can get my Autolite 4300 rebuilt ( it is pretty shot )

- Mildly modified cam

- I already put a Pertonix in the distributor as I was pulling my hair out on the points

- The transmission is a C-6

 

Does this make sense ? I'm looking to take the car from the stock 280 HP to the low to mid 400's with these modifications. This is a weekend cruiser where I'd like to have some more "punch" and it will not see a track. I don't really care about MPG...it's pretty bad as it is. Would like to have it run well on pump gas ( 91/93 )

 

One of my concerns is around cooling. The car has the original radiator that was re-cored years ago but it runs a little hot on hot summer days in traffic. It does have the temperature vacuum switch but that doesn't do much on a 100F day. Again I want to keep the car looking as stock as possible ( all the way down the dog dish hubcaps etc ).

 

Any suggestions appreciated !

Thank you !

 

Tom

1971 Convertible, 351C 4V, Grabber Yellow.

Link to comment
Share on other sites

.

ok, cool project but we need to know your rear gear ratio.

 

for your app, i would run a blue thunder base model intake period.

 

i would throw that 4300 in the trash and run a demon or quick fuel annular booster or downleg booster carb . . either around a 680 mechanical secondary or 750 vacuum secondary.

 

throw on some factory style aluminum valve covers to match.

 

roller cam is best but it will run well with a non roller for your app . . something like a comp xe282h or similar is the biggest i would go in your app.

 

you will need headers . . 1 7/8" tubes should be fine.

.

Link to comment
Share on other sites

Your goal of middle 400s is very achievable. Given how you said you want to use the car, a true street car, I'd opt for a 408. Cubic inches rule for the smile the extra torque brings to your face. Scat makes a good "cast steel" crank and I beam rods and Mahle makes an excellent dished piston and ring package that should net about 9.5:1 depending on deck height and actual chamber volume. A flat tappet cam will work fine for this application. Upgrading to an adjustable valve train and better rocker arms, will open up the spectrum of cams to choose from. For a few dollars more a "quasi custom" cam may be the best solution. Headers vs. exhaust manifolds will change cam selection as will gear ratio and convertor stall speed if it's an automatic transmission. The Blue Thunder is a very good intake and has a near stock appearance. The stock D0AE-L intake can be used (with a power penalty) with one minor modification and an open spacer, if your desire for originality or budget limits your choices. The 650 will work but, you will be leaving about 15-20 HP on the table. The Autolite 4300A is only about 600 cfm and not well suited to performance work. There are only two or three people in the country that know how to make them work and they aren't talking much. There services can be hired though.

The most critical factor is finding a very competent, performance oriented machine shop. "Good enough" just isn't. If the budget permits, sleeve the lifter bores as the best oiling modification. Don't scrimp on valve train components. This mistake bites many people in the end, or other parts of the anatomy. If you do not have OCD tendencies, develop them for the build. Question everything, including what I'm saying. Check everything two and three times. Spend the time doing the research to make sure the parts you are selecting are well suited to each other. Make sure the entire drivetrain is up to the task of holding and transmitting the extra power. Let us know what you decide to do and good luck.

 

Chuck

Link to comment
Share on other sites

Your goal of middle 400s is very achievable. Given how you said you want to use the car, a true street car, I'd opt for a 408. Cubic inches rule for the smile the extra torque brings to your face. Scat makes a good "cast steel" crank and I beam rods and Mahle makes an excellent dished piston and ring package that should net about 9.5:1 depending on deck height and actual chamber volume. A flat tappet cam will work fine for this application. Upgrading to an adjustable valve train and better rocker arms, will open up the spectrum of cams to choose from. For a few dollars more a "quasi custom" cam may be the best solution. Headers vs. exhaust manifolds will change cam selection as will gear ratio and convertor stall speed if it's an automatic transmission. The Blue Thunder is a very good intake and has a near stock appearance. The stock D0AE-L intake can be used (with a power penalty) with one minor modification and an open spacer, if your desire for originality or budget limits your choices. The 650 will work but, you will be leaving about 15-20 HP on the table.

 

 

The Autolite 4300A is only about 600 cfm and not well suited to performance work. There are only two or three people in the country that know how to make them work and they aren't talking much. There services can be hired though.

The most critical factor is finding a very competent, performance oriented machine shop. "Good enough" just isn't. If the budget permits, sleeve the lifter bores as the best oiling modification. Don't scrimp on valve train components. This mistake bites many people in the end, or other parts of the anatomy. If you do not have OCD tendencies, develop them for the build. Question everything, including what I'm saying. Check everything two and three times. Spend the time doing the research to make sure the parts you are selecting are well suited to each other. Make sure the entire drivetrain is up to the task of holding and transmitting the extra power. Let us know what you decide to do and good luck.

 

Chuck

 

+1 with what Chuck says. Research everything and match the parts.

-john

(jbojo)

351C 4V cc heads, 10.5 : 1 CR, 290 Herbert cam, Flat top forged pistons, forged connecting rods, Atomic efi,

C6 with Gear Vendor overdrive, 3.89 Tru Trac, Hooker Super Comp with 2 1/2" Pypes Exhaust.        

 

Some Mod pictures can be seen at: [button=http://www.7173mustangs.com/forum-garage?filterxt_uid=2026]Bojo's Garage[/button]

 

 

Link to comment
Share on other sites

Welcome from West Texas!

 

A stroker kit's not a bad way to go, lots of the guys have had good luck stroking their engines so it could be a good way to go. If you go that route, while you have it all apart, you might as well address some of the other things that will help make power, such as the heads, intake, and exhaust - that's where a lot of your power comes from. Better breathing means more power.

 

My engine is a 351C-2V (H-code) and I've punched it out to 400-ish (according to numbers provided by CompCams) by changing out [from stock specs] the cam, intake manifold, rocker arms, pistons, carb, ignition, and exhaust system. Everything done to my engine can be made to look factory with the exception of the carb, intake manifold, and headers... which even the intake manifold could be painted to match and most people wouldn't even notice. Then trade the chrome valve covers with stockers and go with painted headers and it's looking pretty much like a factory set-up again.

 

attachment.php?aid=31460

 

Some of the things I've done:

- Rebuilt the 351C-2V with:

-- .060" bores w/9.5:1 Keith Black hypereutectic flat-top pistons

-- CompCams Roller cam 274/274 w.566" lift (.218/.218 @.500" on 110 lobes)

-- CompCams Roller "Everything" (1.73 Rockers, lifters, rods, rod guides)

-- Crane Cams screw-in 7/16" rocker studs

-- Edelbrock Performer intake

-- Edelbrock Performer 600CFM carb

-- 3-angle valve job & hardened seats (rebuilt the stock 2V heads)

-- Mild port & polish (mostly port matching and clean-up)

-- Chrome 'stock' oil pan

-- Canton windage tray

-- Edelbrock chrome valve covers

-- Holley "Black" electric fuel pump

-- Duraspark ignition

-- Accel Super Coil & 8mm wires

-- Hooker Competition Ceramic-coated Long-Tube Headers

-- Pypes 2.5" stainless exhaust w/X-pipe

-- Pypes Street Pro mufflers

 

Hope this helps!

Eric

mach1sig2.gif

Link to comment
Share on other sites

Welcome to the forum. That sounds like a fun project. Your options are endless and it all boils down to what your really want. 'Generally' the more horsepower the less 'driveable'. This is more true with these older engines that cannot adjust certain variables for different RPM's and load.

 

But it's not a linear scale. Two Hundred to three hundred horses lose you less driveability than 400 to 500.

 

I am going to go against the grain of my well respected forum members and suggest you go with a roller cam. Do some research on the differences. The major downside to roller is the cost but there the advantages are worth understanding.

'Mike'

73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

 

Pics of modifications included in: [button=http://www.7173mustangs.com/thread-1973-convertible--3335]My Garage[/button]

 

Link to comment
Share on other sites

Welcome from Oklahoma. Great info provided here!

 

"trying to keep it as original as much as possible" ::thumb::

 

:blush: Ray

1971 Boss 351  

1972 Q code 4 speed convertible 

1971 Mustang Sportsroof  351-2V FMX 

1971 Hardtop (parts car)

1973 Mach 1 (parts car)

Link to comment
Share on other sites

Welcome from coastal Alabama! I can't add much, if anything, that hasn't already been said. I trust Chuck's advice 100% oncluding his own advice to question everything. The others also have sound advice. I'm a can of annular boosters as well. Keep the 4300 on a shall as a conversation piece.

spacer.png

Link to comment
Share on other sites

Hello Everyone !

Thank you for the advice, greetings and suggestions. Have a lot to think about here.

One more question - I hope somebody might be able to help with:

I replaced the stock distributor with an MSD Ready to Run ayear ago. When I installed it and got it running, noticed that my OEM air cleaner would not fit (%@"@&^%).

When I do the rebuild I'll throw a new distributor in the car. Anybody know of one that will fit under the stock air cleaner ?

 

Thank you again!

1971 Convertible, 351C 4V, Grabber Yellow.

Link to comment
Share on other sites

Hello Everyone !

Thank you for the advice, greetings and suggestions. Have a lot to think about here.

One more question - I hope somebody might be able to help with:

I replaced the stock distributor with an MSD Ready to Run ayear ago. When I installed it and got it running, noticed that my OEM air cleaner would not fit (%@"@&^%).

When I do the rebuild I'll throw a new distributor in the car. Anybody know of one that will fit under the stock air cleaner ?

 

Thank you again!

 

Yup. http://www.7173mustangs.com/thread-distributor-and-ignition-info-thread

spacer.png

Link to comment
Share on other sites

I am a big fan of the stock distributor with a pertronix upgrade.

 

If you do not have a stock distributor laying around just buy a rebuilt one from the local auto parts store and toss the points in the trash. They are super cheap.

 

The manager at the local O'Reillys is pretty cool and the last time I needed a stock dist he had the warehouse look through their stock and pick one with a D1 part number on it. We do not normally go to this level of detail but he offered and I accepted.

 

A Pertronix by itself is perfectly fine for the street.

 

A Pertronix with a MSD 6AL is a great set up. If you have a tach then add a MSD Tach driver - Life is good!

 

http://www.pertronix.com/prod/ig/ignitor/default.aspx

 

- Paul

Link to comment
Share on other sites

I'm sorry - I forgot to mention that the Duraspark conversion on mine fits under a factory Ram Air air cleaner without any kind of modification.

 

Using a stock distributor with a Pertronix module will work as well.

Eric

mach1sig2.gif

Link to comment
Share on other sites

::welcome::Why not take it 'all the way'! You got a lot of the makings and modifying is modifying. I'd sure love electric window. Have all I want in mine except Edelbrocks 'new' Air Gap for EFI unit(note mine does not have PS, however only have to worry about the lack of this comfort is when it is doing a U or K turn. LOL) Though would like somemore stiffening of the suspension like Kit Sullivan's and a little more heighth

1_12_09_14_11_07_03.png
Link to comment
Share on other sites

Welcome from Massachusetts. I hope you find the answer to your cooling problem here, there are a lot of very knowledgeable people on this forum I'm sure somebody has the answer.

Going fast is fun but life is short so slow down and enjoy the ride :D Frank

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...