Boss 351 Engine or not??

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Djustham

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I have a 1971 Mach I that supposedly has a 351 Boss engine in it.  Its not the engine that came in the car so the vin number wont help. Where do I look, what do I look for to determine (numbers on the engine) if it is a true Boss 351 engine? Guessing its based on the carb and intake manifold?  

 
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It's easy to change carburetors and intake manifolds.

A Boss engine block casting number will be D1ZE-A or D1ZE-B. The heads casting number will be D1ZE-B.

The intake manifold casting number will be D1ZZ-9424-F

 
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It's easy to change carburetors and intake manifolds.

A Boss engine block casting number will be D1ZE-A or D1ZE-B. The heads casting number will be D1ZE-B.

The intake manifold casting number will be D1ZZ-9424-F


@Don C, not sure where you're coming up with those numbers. 

B351 intake is D1ZX-CA, heads are D1AE-GA, same as 71 M code, but with screw in studs & guideplates. Block is *usually* D0AE-L, same as late 70 351C, but with 4 bolt mains and has to be within certain casting dates. 

I have a 1971 Mach I that supposedly has a 351 Boss engine in it.  Its not the engine that came in the car so the vin number wont help. Where do I look, what do I look for to determine (numbers on the engine) if it is a true Boss 351 engine? Guessing its based on the carb and intake manifold?  
Block casting # is above starter, heads casting is on underside of intake ports, which requires the intake to be removed.  

B351 had unique connecting rods, crank, balancer, dipstick, domed pistons etc etc. A good place to familiarize yourself with the parts is  :  http://www.mustangtek.com/

 
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@Don C, not sure where you're coming up with those numbers. 

B351 intake is D1ZX-CA, heads are D1AE-GA, same as 71 M code, but with screw in studs & guideplates. Block is *usually* D0AE-L, same as late 70 351C, but with 4 bolt mains and has to be within certain casting dates. 
And if a person has a suitable camera tool, you ought to see this piston, unique to the 351Boss. Also, I believe the head volume was larger at 67 cc instead of 63 for the M code. There is some conflicting information on this.

Boss piston.jpg

 
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From various sources, for instance, what I show on the intakes for D1ZX is that it is a "unique competition part" and D1ZZ is for the 351 (C) Boss. May be some confusion between casting numbers and part numbers, on my part.

 
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+1 on D1AE-GA for Boss 351 heads. The Boss 351 heads were also machined for spring cups. Chuck

 
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Sorry for my confusion on the parts versus casting numbers, D1ZZ-6009-D is the part number for the Boss 351 block assembly, D1ZZ-6049-B is the part number for Boss 351 head assemblies, and D1ZZ-9424-F is the part number for Boss 351 intakes.

 

donkost

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Long time Pontiac guy, jumped ship, now driving a '71 Grabber Green Mach 1 with "J" code 429 Cobra Jet, close-ratio 4 speed, 3.50 Traction-Lok rear.
It would draw a lot of flak from lovers of other marques, but I have felt for a while that the '71 Ford Boss 351 might just be the best factory small block V8 engine ever manufactured.  Perhaps I should say smaller displacement engine rather than small block, you get the idea.  There is also the '70 Chevrolet LT-1 350, a potent combination in its own right, but I still hold the Boss 351 in higher regard.

 
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Ive got D1ZX-9425 on the intake manifold 

View attachment 43610
Nice, but PLEASE do yourself a favor and replace that damn gear clamp on the fuel line with a correct fuel line clamp, either crimp style or 'tower' style. Gear clamps are fine for temporary use, but not only do they look like crap, they tend to fail. I'm sorry to beat you up, not my intention, I would hate to hear about a great car going up in flames.

 

SVO2SCJ

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Hello

Well from you first post (showing you don't know), and your second post (with photo) showing a CA manifold BUT NOT a D1ZF-ZA carb............I would ask that you LOOK AT THE THICKNESS of the balancer behind the lower crank pulley next!

You need to see if it is 1" in width it is a 351 Cleveland or if it is 2" .   There is more than that to do for your forensics, some you can do without disasembly some where you have to remove parts.    IF you are not restoring, selling or need help rebuilding then leave it at that.   IF you are doing any of the above then reach out to someone that knows (read don't listen to friends that don't) before you make any move, mistake or cost yourself money.    

If it turns out you just have an engine that a Ford Boss alum manifold was installed on (and running a Holley spread bore) fine.    If they cut it (and running a Holley square bore) fine.   Again, once known what you want to do then you can put the work into figuring out.  All the date codes will tell you is if it is a 1971 or 1972 R motor.  To know if it is intact inside you have to take apart (or do some forensics)

Happy to help

Mark 517 861 7630

P.S.  I learned a long time ago that you don't sell to people that appraise things!  So before someone says "do you want to sell"  call.   We all know the people that would reply that way.   At the same time "you can't sell a secret"  so call.  

 
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Djustham

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I bought the car bc I like it and want to make improvements to it and go out and polish it and admire it and every so often on a nice day drive it.  I appreciate the comments relative to the worm clamp and anything I can do to keep it somewhat original and also make it better.  The topic of whether or not its a Boss 351 engine, as the seller stated and the seller before him stated is just a matter of my innate curiosity at this point.  DO I want to tear the motor apart to find out, no.  So I have attached a bunch of pictures and if you want to make comments, good or bad or advise things I can do I will appreciate all comments.  If you see anything one way or another to lead you to believe it is or is not a Boss 351 engine, let me know.

Thanks

DonIMG_1265.jpg IMG_1264.jpg IMG_1255.jpg IMG_1256.jpg IMG_1261.jpg IMG_1258.jpg IMG_1263.jpg

IMG_1257.jpg

IMG_1254.jpg

 
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Hello Djustham,

First I'll say what a great looking Mach1 you have.

It would be a check in the plus column if you did have a Boss engine. Depending on how long ago the original engine was replaced , it could certainly be possible. Before these engines elevated to cult status, it was much easier to find Boss engines and parts in a  salvage yard. I remember in early '81 I was approached by a person looking for some Boss 351 rods, pistons, and damper. He had been looking for an engine for a project and this one fell into his lap from a salvage yard.There had been zero interest in this engine from anyone looking for a "Regular" 4bl 351. Guess the solid lifter noise and adjusting valves scared off the tire kickers. I personally like the sound of solid lifter Ford engines. I grew up to the sound of solid lifter 427, 271/289's, and Boss engines, pure music!  Oh, and the project, he was mounting a 55 Chevy body on 4x4 F150 frame!

You have already received a lot of really good ID info. The Mustang Tek site, while not always 100% correct, is a good source for ID info. There was a replacement for the earlier mentioned damper. The original is part# D1ZZ-6316-B (ID# D1ZX-AA) . There was another that was the production installed damper for the '72 351 HO and the service replacement for the '71 engine. Ford part# D2ZZ6316-A (ID# D2ZX-AA). So running changes and service replacement parts can also add to the fun of trying to ID certain parts.

Just as a reminder, any number you see on a part is always going to be an engineering and not a part number. Ford NEVER cast, molded, stamped or printed the actual part number on any part. As SVO2SCJ posted, there is a lot that can be investigated without going into the engine. There are many of us that have had experience with these engines in one form or another. So if you need ID help or just have questions, don't ever hesitate to ask. That's why we are all here!  :classic_smile:  

 
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Boss engine or not, you have one nice looking ride there.  Enjoy it regardless!

However, as others have said, you can take a look at the damper, which is probably the easiest thing to do.  Other fairly simple things to check would be to pull a valve cover to see if you have the Boss screw in studs/adjustable rockers.  I believe someone else mentioned it already, but you could pull a spark plug and take a look at the piston with a snake camera.

 
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SVO2SCJ

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Thanks for coming back, posting photos and keeping involved here and with your car !     I think we all assumed it was a project and ratty. LOL  Very nice car.

Though not the photos , I hoped to help tell.....at this point I would simply (get a look at the balancer) and TELL US "does it sound like a SOLID cam shaft".   If it doesn't and doesn't have a 2 inch balancer........seeing the lack of Boss parts and the pletora  351C parts leave it at that!   Move on to your work at hand.   

To your idea of "working on" what to do, I would adress all of the WRONG /missing items from what I CAN see it the photos.   Look at photos of hose routing for air cleaner AND CONFIRM "what is the hell did they run the canister hose to" ??????!!!!   I'm not sure I would put effort into the 2Brl air cleaner - rather consider finsihing the car with the correct ram air!  If you detailed the engine compartment and un "H" coded it you would kill two birds with one stone!

Chris cars 040.jpg

 
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