Keep it original?

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goforbroke

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1973 Mustang Grande, Light Pewter
351C H code w/FMX transmission.
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So I have this 73 Grande with 23k original miles, and as many of you know, these are 351c engines are turds with all the smog restrictions in place (California car). As a project, I've been tempted to pull the heads to have a machine shop install hardened valve seats. Of course, that would be a good time to upgrade the cam, and timing gear/chain. I've been tempted to ditch all of the egr equipment in the process. Do you think doing any of that would diminish the value, and ruin the originality of the car?

 

TommyK

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So I have this 73 Grandé with 23k original miles, and as many of you know, these are 351c engines are turds with all the smog restrictions in place (California car). As a project, I've been tempted to pull the heads to have a machine shop install hardened valve seats. Of course, that would be a good time to upgrade the cam, and timing gear/chain. I've been tempted to ditch all of the egr equipment in the process. Do you think doing any of that would diminish the value, and ruin the originality of the car?
IMO replacing valve seats isn't going to hurt the value of the car. BTW you should also replace the failure prone original valves while your in there.

On a low mileage original car, deleting the emissions equipment may diminish the value in many buyer's eyes.

 

Bill73Ragtop

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former owner (25 yrs) of 1973 Convertible, 351c, A/C, RA
From my experience the value is not going to change much for the changes you propose. The car's value will be more likely based on overall condition of body, interior, engine compartment, etc.. You obviously DO need to keep any removed emissions equipment in case the next owner wants to reinstall it. And probably the only way it would be re-installed is for someone intending on showing as concours factory original appearance in national level like MCA or AACA or in a museum. If you plan on showing the car as original, you should most definitely keep it in place.

Making internal improvements will enhance your enjoyment of the car, but don't expect a significant increase in value from that type of work.

 

Hemikiller

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If it's truly a 23k mile unrestored, all original car, I'd keep it as factory as possible. Too many of these cars were ripped apart and used for parts, others given the 70's Skyjacker treatment with junk tacked all over them. It's a pleasant surprise to see a very original, non- Boss/Mach/superduperspecialedition car at shows. We have a local couple that have a 70-something Pinto that is as mint as mint can be.

It very easy to simply block off and disable the EGR system, while leaving it intact as an original appearance item. A few strategically placed ball bearings in the vacuum lines fixes the problem. To be honest, you'd probably never even notice a properly functioning EGR system doing it's job.

Given that the car is heading for 50 years of age, it would be wise to do some general maintenance items. Valve seals are probably falling apart by now and heading for the oil pan. If it has the original nylon toothed timing set, that's a time bomb waiting to go off. The engine probably could use a re-seal, cylinder hone and set of a rings and bearings, mainly because it spent so much time sitting around.

As far as hardened valve seats, that's a waste of money IMO. With 23K, it should have nearly zero wear on them and they really aren't needed unless you are towing or doing long distance high rpm runs. Depending on you plans for the car, I don't see the need to replace the valves unless it's high performance you're heading towards.

 

goforbroke

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23k original miles
Appreciate all the feedback! It is a 23k mile car that has been passed down through three generations. Everything is original on it except for the usual wear, and tune up items, with the exception of some of the a/c parts that needed to be replaced to convert over to 134a. Here are some photos...











 

goforbroke

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Also, out of curiosity, does avgas have enough/too much lead to be beneficial or harmful?

 

Lazarus

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Man, that’s a beautiful car!  Really like that color with the vinyl roof. 

I usually have absolutely zero hang-ups about originality, but then again, I always buy less sought-after models so I can build however I want without regret.  That said, if I had that one I’d maybe leave it original, or at least change nothing that could not be undone, and save all parts. Just one man’s opinion. 

like I said... really cool example of one of our cars!



 

Don C

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You can get 100LL (low lead) that should have enough lead to keep the valves lubricated. You have to realize that it's illegal to use on the highway, both from an environmental aspect (the lead emissions) and political (not paying gas tax).

 

Spike Morelli

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Being an ex-aircraft mechanic, I've had the opportunity to run 100ll in my Mach 1. It runs great. The 100ll has a different specific gravity to the fuel, and may, in some cars, alter where the float level sets, but had no adverse effects with my car. My car did run a tad leaner, based on tailpipe soot color.

About your Grande', it shouldn't "as you know" run like a turd. The smog equiptment is only a small part of how it runs. There's no smog testing of your year car in Calif, so go ahead and remove what you feel you'd like to. Always keep the PCV operable, as it has more benefits than downside. If you are going to replace the camshaft, or timing assembly, remember that the crankshaft gear probably has the retarded timing mark like so many Fords in '73 were built. Use a early timing chain and gear assembly, like from a '70-'71, or an aftermarket set, to get the bottom end back. A good tune-up should bring the car into more than acceptable feel. Heck, I've driven some six cylinder cars that were pretty snappy I thought.

 

JD79

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Beautiful car! I would keep it original if it was mine. Since it is a 1973 , my understanding is that you don’t need leaded fuel . The 1971 and 1972 apparently do need leaded fuel. Maybe somebody else on the forum has more info regarding the leaded fuel requirement....

 

7173Vert

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Like ‘em original or original restored. This one is a 50k orig mi Canadian vert out of Victoria, BC. Most of the green paint is still original, they did repaint the ps rear 1/4 panel after a very minor ding on the lower wheel area. Even the top is still original but will need replacing at some point. The lovely :) Avocado interior is in mint shape. Even has the rare optional leather wrapped steering wheel. Clearly, I like to keep them factory as they are all being resto-modded today... Your choice in the end as to what you do with your car, enjoy.

 
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Taking the pollution control off that car will yield you nothing. Putting hard seats in the heads just adds another failure point. I have a 1956 Ford that only had Pure White Gas or unleaded all of it's life and was parked with over 90,000 miles with no issues.

Use the Lucas gas additive that replaces the lubrication of the lead. I have a 351 H code bored .050"over flat top pistons, cam and 4-V on the 2-V heads and have no heat issues.

You can leave all the smog stuff on and just plug vacuum ports and they do nothing.

These cars do not run like the new cars and never will.

Your car might need valve stem seals with age but would not tear it down can be put on without pulling the heads. They are only original once.

 

Don C

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My personal experience with valve recession was from a '74 390FE that I had transplanted into my '64 F100 in 1976. After about 10 years it started running like crap. Some of the valve seats were recessed to the point the valves would not seat.

 

Mister 4x4

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I have to agree with David here: unless you're addressing a specific issue, I'd stick with simple periodic maintenance since it's such a nice, low mileage car.  Obviously, it doesn't get driven a lot... but that doesn't mean you don't want it ready to go when the time comes.  Plugs, wires, filters, fluids, timing & points should continue to keep it happy & reliable.

Now, if you're really intent on warming things up, there are a lot of things you can do to keep up cosmetic appearances, while increasing performance.

  • Pertronix ignition to eliminate points
  • Block-off the emissions equipment to render it inert
  • Swap in 4V stuff (intake, carb, heads) OR 
  • 351C-2V 4bbl intake (like an Edelbrock Performer), dress and paint it to match the engine, then get a 4bbl carb.
  • Swap rear gears to 3.50s (instant off the line improvement)
  • Upgrade the cam and valve train to roller 'everything' (which eliminates friction, and improves flow with a stronger mild cam upgrade)
  • Upgrade to a mild performance muffler (a Magnaflow will increase flow without making it sound like a race car) 


Most of those ideas would be fairly invisible to the casual observer.  The most obvious change would be the aftermarket intake and 4bbl carb.  As well, performance gain isn't going to be huge, but it might just be enough to put a smile on your face.  How much that's "worth it" is up to you.  It all depends on what you want to do with the car for the future (preserve it, or have fun with it).

Good luck - hope this helps!

 

mrxerox

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I vote new intake and sniper EFI with holley distributor so sniper can control timing as well. $1500 and that car will be so much more enjoyable. I know most of this forum are die hard carb guys but do some research about the sniper before you run out and buy a new carb...

 
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You gotta keep that one as original as possible imo. With that low of miles and the documents to back it up, it needs to be kept more on the original side. Sure, you can definitely get it running a bit better, but you don’t have to change a bunch of stuff to do it either.

By the way, welcome to the forum and that is a really nice ride you got! Hope you have good luck and lots of fun with it!

 

73' mach 1

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I'm going against most here but here is my take. Why did you get the car? Did you get it to hope to eventually sell is as a high dollar original car? Did you get it because you absolutely love that style and want to enjoy it how you want? 

I fell into the rabbit hole quickly when things started coming apart. Everything that came apart turned into "well, while I'm in there". My car was a 36K original 73 mach 1 Q code. I knew right away I had no intention of ever selling this car for profit but I still kept everything that came off this car. Just be aware of the bug. What started out as a heads and cam has turned into an hydraulic roller EFI 408c with TKO 600. 

I'm of the mind set that you only only live once so do the car however YOU will enjoy it most. If you're that uncomfortable cutting into that low mileage car than sell it for as much as you can get and buy a higher mileage one and build it the way you want. Just my .02

 

MikeGriese

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I would be firmly on the side of keeping it original. That car is a time capsule. I bet if you look underneath you can still see some of the factory assembly and part ID markings. Scratch the urge for a pavement shredder with something that is more distressed.

 
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