my 351 Cobra Jet

[72Chero]

I was unaware that this motor existed until I bought my Chero.

I was aware of the 428's but not the 351. I've learned much about the Ford's since I've owned this one.

http://www.supermotors.net/getfile/246628/fullsize/8873434-r1-034-15a.jpg

http://www.supermotors.net/getfile/205568/fullsize/023_20a.jpg

http://www.supermotors.net/getfile/205660/fullsize/021_18a.jpg

We just rebuilt this motor last february. It is bored 40 over, the Closed chambered heads have been milled .008, Stainless valves, speedpro flat top pistons, Edelbrock performer manifold, Lunati Solid lift race cam, Roller rockers, Holley 750 cfm, Hooker supercomp headers, Weind water pump, Melling high vol oil pump....just to name a few. This has to be the most fun I've had driving since....the race car. Backed with a 4 speed toploader and Richmond .389 gears in the posi...makes for a lethal weapon.

[Mongoose]

Wasn't one of the rarest Mustangs the Boss 351? Didn't that have the 351 Cobra Jet Engine? Was that in 1970?

[72Chero]

The Boss 351 and the 351 Cobra Jet are two different motors. Similar but the construction of the heads and they way they are assembled seperate the two. Yes the Boss 351 is a very rare Mustang...but as for the Ranchero's mine is up there in the scale of rarity. When I was at the Wild West Auto Fest a couple weeks ago, there were alot of mustangs there showing off there Marti Reports....I had lower numbers than any of them. But its the Boss 351 heads that make the two different. Hope this helps.

[THEL78ISGREAT]

Those Boss 351s could really move, even in those heavy Mustangs

[74runner]

nice....wish that my scanner worked so I could show off my RR

[RiversideParish]

Those Boss 351s could really move, even in those heavy Mustangs
13.72 @ 104.28 in an (otherwise) stocker with headers.

[73ranchero]

I checked my books on the heads and the only difference between the Boss 351 and the CJ is well nothing, The boss 351s and CJ came in either a four bolt main design or not, They all had same valve sizes and same 4v ports. Boss 351 came in Mustangs in 71-73, 351 CJs came in Torinos and Rancheros in 71-73 as well as mustangs

[CJguy]

Actually the only thing in common between the 71-351CJ and the 71-Boss351 is the block, provided the CJ has a 4 bolt main, which some did not.
The Boss351 crank (4MA same as the CJ ) was selected for hardness and can be identified by a Brinell hardness test mark on a polished counterweight. The 4 bolt main caps were also selected for hardness.
The rods were also different, D1ZZ-A, they were shotpeened, magnafluxed and used 180k psi rod bolts.
The pistons were also different, the CJ had flat tops and the Boss had pop-ups. The heads were different as well, The CJ had open chamber, approx 75cc, heads with a hydraulic cam and the Boss had closed chamber heads, approx 66cc, with fully adjustable valve train with mechanical cam (290 duration, .477 lift)…
R- code 71 (Mustang only) Boss 351 engine was only available in the sportsroofed Boss 351 model, 71 only year for a Boss351, 72 had the 351HO...

[Daffy]

Interesting...I didn't know there was a 351CJ in 71...I always thought it was a 72-73 deal..

[CJguy]

Yep sure was,
In May 1971 the M code (351C-4V closed chamber heads)was dropped and Q was given to the 351-4V with open combustion chamber heads, thus the begining of the 351CJ..

[WINGNUT]

The Boss 351.............the last killer Mustang.