Is one 351w better then another???

mustangman70

Founding Member
Dec 30, 2001
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St pete, Florida
On friday im picking up a complete 351w block from a friends dad, he dosent know much about the internals, but he knows it came out of a 79 ranchero.

Im building a 408 stroker out of it and i just want to make sure this is not a bad block to use :shrug:

Other then that post up a nice combo for a 408 :spot:
 
since you are building a large stroker from it, it's a given that you will be changing the heads.

In that case, no, there's no real difference in blocks. There's no 4-bolt main 351W (except maybe aftermarket), so thats no concern. If the Ranchero block tests out OK, go for it.
 
mustangman70 said:
Thanx for the reply man, would it be worth it to have the machine shop install 4 bolt mains :shrug:

No, don't do it. The main bearing webs do not have enough meat to support 4 bolt mains.

The 351w block is good to around 550hp so don't worry about it. The stock main caps are already fairly beefy.

For anymore than that, plan on buying a good aftermarket block.
 
Pre 72 the blocks had higher nickel content and thicker main webs. The change was to reduce weight and cost. 73 and later blocks are still pretty stout though. Maybe the change was in 74? My memory is hazy right now.
Use a main girdle to help brace the caps if you plan on using boost or Nitrous though.
 
69-72 had better iron and were heavier.
After that, they use cheaper iron and get thinner progressively over the years. They were looking to lose weight for economy/emissions purposes.
If you are talking heads, 69-75 are the best, with the 69-73s being best. The 74-75s had more emissions plumbing, but still had the large valves/small chambers/large ports.
If you want a stronger bottom end, use ARP main studs, and combine a girdle in there too if you really think you need it.
Good luck
Dave
 
There is a difference. I think it was 1974 that Ford increased the deck height slightly to help reduce compression. This is actually better if you are going to have your block milled. I have read that early blocks after small amounts of milling would have the pistons actually rising above the block deck surface. Thicker gaskets would be needed to compensate for this. Your block should do just fine but the early heads are better. I have heard that there no difference to the nickel content of early blocks. Can't verify or disprove though.
 
I don't think many of us have the dough required to split a 351w with a girdle. I have personally seen them go 6.30's in the 1/8 on the bottle, and it was a 408. And there are tons of guys making 800rwhp on the net in blown apps. Hell come to think of it, one guy was running stock everything and was going 6 flats in the 1/8. Granted the piston and rods are forged stock.
 
69-74 blocks had more nickel content
69 only blocks had the shorter deck height and maybe the 70 blocks. for sure the 71-up blocks had the taller deck height.
after 74 the blocks got weaker due to the nickel content and thinner webs and decks.
94-up blocks were setup for roller cams and apparently they were thicker and had more nickel content due to their primary use being f-series trucks, can't prove ior disprover this though.
marine/industrial blocks are also stronger for the same reasons maybe even more so than the truck blocks.