[Mach1Medic]

I recently purchased my dream car.... a 1972 Mach 1 (Medium Bright Yellow/Black) 351 C 2-V; 2:73:1 "airplane" gears, FMX tranny. This car is in great shape, considering. I will be repainting the car factory original colors and adding black hood callouts.

I would like to have a good amount of power in this car and for it to be a fun weekend ride (I don't want to have to spin 5500 RPM to hit her sweet spot). Also, I need somewhat economical options. I will do some highway travel. I will be leaving my wedding in this car 04/27/2013.

I have a 351C 2 V motor to rebuild. The car came originally with the 2-V Cleveland but rated at 177hp, and by all accounts I have read this engine was somewhat lazy and lacking torque. I know I will need to change the gears....suppose to 3:50:1? I have read/heard varying opinions about 351C 2V and 4V builds. I am interested in opinions/suggestions as to changing to 4V (I have access to a set of quench chamber heads), staying 2V with mods, or the 2V heads with compatible 4V intake and carb setup. I hope to access the wealth of experience on this forum and make educated decisions to provide proven results for my dream car and future fairly heirloom.

Thanks in advance for all the info and support!
I look forward to utilizing this great resource throughout this project!

 

[cindys_sn95]

stay with the 2V heads, will be much more street friendly. 3.55 gears will wake it up!

 

[sporty12]

Put a stock rebuild on the short block, might add a small( auto trans friendly) cam, after market intake, quick fuel carb. in the 600 to 650 range and a set of long tube headers. with the 3.50 gear should run pretty good, and be a good street machine. I owned 2 351C 4v mustangs back in the day.

 

[Mach1Medic]

Thanks cindys_sn95!

 

[Mach1Medic]

Sporty12- Thanks for your advice!
Were you suggesting I stay with the 2 V setup, change to 4V setup, or 2V heads w/ compatible 4V intake and carb?
Any recs on the intake and carb? (I have heard Edelbrock performer is a good option for this motor)
Also, I noticed you were lucky enough to own 2 new Mach 1's..I have been told the 351C motors were always "down rated" on paper for insurance purposes during this time. Is this factual or were there things with all these motors (like the retarding of the '73 motors) that really made all of them not reach their potential?

 

[sporty12]

If you are going to use your car on the street you will likely be better of with the 2V heads. If you can snag the 4V heads for cheap, you might get them and put them up somewhere in case you want to use them later. Weiand also makes intakes for this engine. Any Edelbrock or Weiand street type mild performance intake should be fine. I like the Quick Fuel carb. Everyone runs them around here, They re made in Bowling Green KY. A 680 vacuum seconary should be a good choice. A small hdyraulic cam would be nice in the 218 duration 495 lift range. Both the Mach ! cars I owned ran good and would run with about anything GTO, GTX , road runners. They both had a 4 speed top loader and 3.91 gear. I think the 70 was 300 hp and the 72 266. The 4V engines like a lot of rpm. A friend had a 71 Boss 351 he kept it all stock and it was a strong car, 330 hp . With the above mods your car would likely be as strong or stronger. Good luck, I am glad you are building a 351C, I wish more people would.

 

[seph10]

If you are going to use this car as a weekend driver, stay with the 2v engine, it is a low compression engine and it will run good on regular low octane fuel,,My 70 mach1 has a 351 c 2v engine with a mild cam,625 cfm 4 barrel carb, headers,magnaflow exaust,,,it makes for a great driver and good on fuel,,,I also smoked a 66 chevelle with a 327 in it,,,so it runs pretty good,,,good luck with your build

 

[Mach1Medic]

Thanks for the input guys. I have spoken to the guy who runs the local machine shop and the following is the build I'm contemplating at this point:

Bore block just to what it will clean up at (0.10,0.20)
Stay with 2v heads
Slight dome pistons (I've been recommended Keith Black) Opinions?
-to bring compression up to around 9:3-9:5 (at most)

Cam options: Comp xe262H 218 duration; 518 lift
-range is 1400-5600RPM. (I was told by Advance
Auto that my FMX factory stall was 1200-1400.
However, they continue to try and sell me C6 parts
so I'm unsure if that info is correct. Anyone know
the fact specs for FMX? Opinions on this cam app?

Rear end: from 2:75 to 3:23 or 3:50

Intake: Edelbrock Performer RPM Air Gap

Carb: Quick Fuel (HR-680-VS)-couldn't see $100 difference in HR vs
SS for my application.

Headers: Hooker (6913)

Please let me know what you think of this set up...I'm all ears for all opinions.

 

[Mach1Medic]

Seph10 what cam do you have? HP & Torque?

 

[Lizer]

I would go with a Performer Air Gap instead of the RPM Air Gap if you're trying to maximize torque...the RPMs are more top end oriented.

 

[sporty12]

I think your cam choice will work good for your car. I would go with the 3.50 gear and look at getting a converter with a little more stall. I think you will be surprised at how good it runs.

 

[Al Newman]

Higher converter stall will take away from the "streetability" and economy just a bit but you probably could live with it. 2V heads with slightly domed pistons is good choice. Standard dual plane Edelbrock or Weiand intake would be best choice, not one of the high rise or single plane units. Carb choice would be more suitable in the 600 cfm, no more, range for economy and throttle response. Your tranny says to me that you don't need any more than 600 cfm. 550 cfm would be plenty good, but nobody would agree with me on that. Rear gear choice would be 3.25 as a suitable compromise for streetability. The 3.50 gear requires an uncomfortable amount of revs at highway speeds. Cam selection should stay relatively mild, as the Cleveland is really sensitive to cam changes. Certainly no more than .480-.500 gross lift. LSA in 110-112 degree range. Dual pattern with a bit more lift on the exhaust side would be good. A little goes a long way. Headers if you must; although the stock exhaust system flows plenty good up to 5,000 rpm.
Best,
Al