How about a Mexican block? It had a lot more nickel content. It shouldn't matter if the block was 2 or 4 bolt mains. He is only asking about the block. You can put whatever guts in the engine you want.

 

The strongest 351 Windsor blocks were made up until 1978 ... had the higher nickel content in them and thicker walls. The Mexican blocks had the most but are very difficult to find. If you are going to 600 HP via a power-adder then you should definitely get the block sonic checked. That will make sure the walls .. especially the outside walls where the most pressure will be from the pistons will be thick enough to take the brunt. For sure the best bet would be to spend the money and get an aftermarket 4-bolt block. Ford Racing's "sportsman" block or Dart's etc. would be the way to go. If you do find the right block you can still easily get the 600 HP out of it pretty safely but boost used all the time is hard on the engine. Good luck.

 

IIRC all 351W factory blocks are 2 bolt and can handle up to 450 hp unless you 'girdle' the bottom end. In any case though, the blocks and other components are much stronger than 302/5.0's.

 

The Boss 351 was a cleveland motor

The car was only the 1971 production year,
However, Ford did put some in the 1970 mustang.
1970 edition of Mustang Magazine with the gold 70 on the cover.

 

so its just a cleve 4v with the "boss" name attached to it?

 

The boss had different heads than the 4V clevland, different carb a 750 Holley, and 11.3 compression. I can't remember the rest.

 

choices

Door #1
Door #2
Door #3
Door #4

 

wait, a cleveland block and it was a "boss" but it DIDNT have the 4v heads which is what made a boss a boss...... wtf heads did they use? aussie's?

*edit* btw i choose door #3

 

We are mixing terms hear. Back then 4v meant 4 barrel carb not 4 valve head, No Cleveland had 4 valve heads. 4V heads were 4barrle Carb heads, they were different then 2 barrel heads and boss heads were different from 4barrle heads in that they had bigger valves and larger runners. Boss heads were also 4V heads in that, the boss had a 4 barrel carb. But different from the 4V or 4 Barrel heads.
I’m confusing myself. , when you talk 429 it gets worse. and 427 is the worse of all cause they made a 427 thatused a 4 valve head (dohc)and they made a 427 4V head that was 2 valve but had a 4 barrel carb. I have to go sit down and get a beer.
Ron

 

i think your confusing yourself LOL
<~ not a noob, i know the cleves were 2 valve heads - as were 99% of all motors until the import invasion of the 80's

a "boss" 302 head is essentially a cleveland 4 barrel head.
a 351C 4V obviously used a cleveland 4 barrel head
so a "boss" 351 is a 4 barrel cleveland, but NOT using cleveland 4 barrel heads?????????????? this is what im getting out of all of this.