Boss 351

[Robb]

Can someone give me the skinny on a Boss 351 engine?

The Boss 302 wasnt just a souped up 302, it was a different block.
Is the boss 351 a similar animal? Or is it something like a relabeled cleveland?

Thanks
-Robb

[mrmustang]

Drop me the casting number from the heads and block, and we'll go from there....


Bill S.

[cobrajeff]

The BOSS 351 is a special version of the 351 Cleveland engine. Although most of the parts are INTERCHANGEABLE, they are NOT common with one another. About the only COMMON parts between the two are the distributor cap, water pump, and nut/bolt hardware. The block, heads, crank, rods, pistons, cam, intake, carb, spark plugs, and distributor are all different.

You must be careful - just like in the old days, when everybody who had a 4V on a 289 claimed they had a "HiPo", most everybody who has a 4V on a Cleveland thinks he has a "BOSS". Probably NOT, they are pretty rare. Let MrMustang set you straight with the casting numbers - don't pay "BOSS" prices for a 351C 4V engine.

regards,

Jeff

[Pantera Tom]

Below is a great link to all the Ford motor head specifications. It shows you the difference on the 351 Cleveland motors and the "Boss 351". The 4v heads have the largest intake and exhaust valve combination and the port size is also bigger, but the one special difference most significant difference is the combustion chamber. The Boss 351 has a closed or quenched combustion chamber which is 62-64cc vs the open chamber which is 74-76cc. The smaller combustion chamber pushes the compression ratio up about 1.5 to 1 more than the open chamber head.


http://home.comcast.net/~jelerath/mu...master-fr.html

[arctic-snake]

I used to have a Mach I in high school with the 351 C-4v and a hurst 4 speed.. Really fun car. But if memory serves. The boss had mechanical lifters rather than hydraulic. And I think it also had a dual point distributor, higher compression etc. Can't remember about the block though. Damn it's been a long time.

[trularin]

Jeff makes a good point, check the PNs.

I pulled my Boss from a 1971 mustang that was wrecked. I sat one it for 30 years before a rebuild and pump up.

The PNs tell the story. The heads will most likely be GA production heads, but they can be identified quickly by the adjustable rocker assemblies. That is not to say all heads for a 351C that have adjustable rocker assemblies are Boss heads, but it is a good place to start.

Just my $0.02

[AK1234]

Most Pantera's came with 4V 351's mine has D2AE-CA blocks 4 bolt mains and D3ZE heads but not solid lifter ............. now a real block is the XE NASCAR block.