Most desirable 351W engine year?

[red67]

What is the most desirable year to obtain for a swap? Are blocks or heads better some years than others? For a performance build up, what block year should one look for?
%) just curious...

 

[Skuzzlebutt]

69/70 heads are considered the best. That's what makes them hard to find. They aren't magical tho, most aftermarket heads are better.

 

[Ryan]

94-up Blocks are roller cam ready number starts with F4 on the block
Explorer GT40P heads are the best production head in stock form, but are a major pain on exhaust headers.
Lightning engines had standard GT40 heads some are roller cam ready
Roush 180 heads from World Products are pretty good for low RPM engines

 

[PABrian]

Do a search on it. There's lots of good info. in earlier posts.

 

[red67]

I have a 70 351W motor in my EB right now that the PO stuck in there. I am having blow by, and I know it is time for a rebuild. I was just wondering if it was worth rebuilding. I heard that some blocks were stronger than others. I was attempting to find out if there was a significant advantage of rebuilding the current motor or just spending a grand on Kragen long block with a warrenty?:?

 

[mustangmarty]

Correct me if I'm wrong, but I heard that the 69 - 70 blocks had a higher nickel content in them and so are better for wear. But then again, they weren't roller blocks like the later Windsor blocks are. I chose to go with the 69 block and have it retro-fitted for a roller cam.

 

[66roadhorse]

The pre 74 blocks had a higher nickel content and in theory are a little stronger. The later blocks had a different rear main seal that is a little better than the early ones. For a bronco, you should be fine rebuilding what you have as long as it has never been rebuilt before.

 

[Skuzzlebutt]

Correct me if I'm wrong, but I heard that the 69 - 70 blocks had a higher nickel content in them and so are better for wear. But then again, they weren't roller blocks like the later Windsor blocks are. I chose to go with the 69 block and have it retro-fitted for a roller cam.

I've heard that too, and you'll hear the same thing about "HECHO EN MEXICO" 302s. Most expert builders say that while it may be true, the difference is so slight that it's really not worth considering.
There has never been any year of W blocks that were considered weak.

 

[Broncobowsher]

What is the most desirable year to obtain for a swap? Are blocks or heads better some years than others? For a performance build up, what block year should one look for?
%) just curious...

This is a bit of a loaded question. The choices depend a lot on what you plan to do. If you just want to pull something out of a junk car and drop it is will be a different recomendition if you want to pick up an engine and do a cheap rebuild, wich is different then if you want to build a high dollar engine.

If you can get an engine in perfect condition that isn't worn out and in need of a rebuild and you don't want to do anything to it, the '69-'70 is the best. the 4V having flat tops and more compression the better choice. Now the chances of finding a 35 year old engine that is perfect are not good.

If you are going to build something, the post '71 blocks have a little more deck height and that is what most of the aftermarket considers a standard 351.

All stock heads suck. The 69-70 heads suck the least. If you don't get 351 heads, the bolt holes on the 289-302 heads can be drilled out. For good heads, look aftermarket if you can afford them.

Late model 351s are roller cammed. This is a great performance/anti-friction upgrade. Also late model blocks are newer and haven't had as much time to wear out. Modern machining has better tolerences then the stuff of old. Also late model blocks have 1 piece seals, much better at controlling oil leaks.

As far as I know, there are no "bad" years for 351s. Some years were heavily smogged, but if you rebuild a '69 and a '79 to the same specs, they will run the same. Don't worry about the factory HP ratings unless you plan to drop in the engine bone stock, including the convertor and air filter.

 

[BUCKETOBOLTS]

Most desirable is going to be left up to the purchaser. Little things like castings, cams, and such can all be worked around. The main thing to remember is that their is no replacement for displacement.