How much is it worth/would you pay

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Joined
Oct 29, 2024
Messages
73
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Location
Las Vegas, NV
My Car
White 1971 Mach 1
Happy Holidays Mustang Family!

I need some sense talked into me because I am having a hard time not letting the budget spiral wildly out of control on my build...

Short story is I have a '71 Mach 1 with a presumably stock '74 351c CJ and C6 transmission. My end goal is to have a respectful street performer (400 hp/tq) with a T5 transmission (definitely not concours and just doing whatever I think is cool). I sourced a used T5 for $500 but still need to source all the swap parts. The engine that's currently in the Mach 1 runs strong and the current plan is to run it and get all the kinks worked out while I get the money together for the T5 swap and an engine rebuild.

One idea I have been playing with in my head is to source a '70/71 m code 351c core to build while I enjoy driving what's already in my car. When the rebuild on the second engine is finished and I have the T5 swap kit, I can spend a weekend plopping the lump in and shazaam, have a completely transformed Mach 1. I can then sell the old drivetrain which is a known solid runner or potentially even throw it in my '71 stock 302 vert that needs A LOT of work.

So a 351 pops on marketplace. He claims it was pulled from a 73. I go to check it out and low and behold is a D0AE-L (with 71 mustang vin). He claimed it ran when he pulled it but no proof. It has 2V heads with Edelbrock performer manifold but when I popped a valve cover, its 1975 2v heads. If it had the '71 4v heads I probably wouldn't be writing this because I would have just bought it on the spot. He's asking $1000 but I haven't seen it run and he doesn't want me to pull a head off to check to see if its been over bored already (I don't blame him). He will give me the auto tranny attached to it as well but I don't really want it. In my mind, this is a gamble that I wouldn't want to spend more than $500 on.

Is this a worthwhile gamble? My dream build would include aluminum heads and roller cam so the 2v heads isn't a huge deterrent from my end goal but I think the asking prices is just too high with too many unknowns. I think the biggest attraction is having the 71 mustang vin on there. My current strategy is to give it another week or 2 and then lowball him to see if he caves; unless the consensus here is to go for it. Or maybe convince him to let me pull a head off but that's not in his best interest. Obviously if I had an unlimited budget I wouldn't care about all this but money is starting to get tight and I'd prefer to be able to enjoy driving the Mach 1 while doing all the engine work on a second engine.

Is it even possible to find a standard bore m code 351c shortblock for $500 or is that insane?

Another silly thought is there is a local guy with '71 Boss 351 heads for sale for $1800...

Hopefully last edit for now: I have also been looking at this. Sent the guy an email but haven't heard anything. https://losangeles.craigslist.org/sgv/msg/d/lancaster-ford-small-block-engines/7805886129.html This guy claims: 351C 4 bolt main fresh .030 block , Magnafluxed, new cam bearings, hot tanked,very rare, 351C 4v Closed Chamber heads used, stock rods and crank, New forged TRW Pistons, 4v stock Holley or Quadrajet style intake, apart, $1,950.00

Please bestow upon me your wisdom kind mustang wizards!

Side note: anyone out there have 1F-229108?
Mine is 224468 so I think this would be really cool in my car but it would be even cooler to put it back in your car!

PXL_20241227_231939369.jpgPXL_20241227_231316046.jpgPXL_20241227_231910673.jpgPXL_20241227_230758614.jpg
 
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Prices are subjective and depend on how desperate the buyer and seller are.

For your purpose, don't necessarily be enamored with the 4-bolt main block. Either the 2- or 4-bolt will meet your needs and the 2-bolt may be had for less, so get the best block you can find. Here in Texas I routinely see M-code engines complete for $1,000 to $2,500.

Get a borescope/endoscope so you can look into the cylinders and see verify flat top or dished piston and the condition of the cylinder walls. You can also use your current block and buy/build some closed chambered heads to add to your known quantity.

I wouldn't trust anyone's fresh build. You don't know the quality of the build or the parts used. You'll still want to tear it down, clean it, measure everything, replace parts, address questionable machine work, and reassemble it yourself.
 
My end goal is to have a respectful street performer (400 hp/tq) with a T5 transmission (definitely not concours and just doing whatever I think is cool). I sourced a used T5 for $500 but still need to source all the swap parts.
FYI, a T5 is limited to 300 TQ... some newer ones claim 330 TQ
Rear gearing, wider and sticker tires will enhance the odds of that trans going boom...

"my '71 stock 302 vert that needs A LOT of work."
jm2c... pull that motor and buy a stroker kit 347ci Scat still offers one.
After you rebuild the 351C 4V CJ, you still have a great motor for the vert....
 
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If you want 400 HP, go buy a prebuilt Blueprint power plant with a warranty.
 
As far as checking to see if its bored or not, I've not had any trouble at all with a borescope. You can stick it in the spark plug hole. I stuck it in my 302, and in 2 minutes can read the 0.030 text on top of the piston. Stuck it in my 351w, and can tell not only that it is 0.060 over, but the exact model number of the piston is legible. I looked that up and know I have +11cc mahle pistons.

FWIW, Advance auto parts are going through some tough times and have a bunch of stuff on clearance. I saw they had a borescope on sale. Its a $100 camera everywhere else, and seems to have decent reviews. I have zero experience with this exact model, but it may be worth it.
https://shop.advanceautoparts.com/p...ble-lens-accessories-included-3380/12564387-P

FYI, a T5 is limited to 300 TQ... some newer ones claim 330 TQ
That may be for a stock T5. The aftermarket has upgrades that push them up to 500tq.
https://www.jegs.com/p/G-Force-Tran...s-And-Mainshaft-Upgrade-Kits/1343713/10002/-1
 
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