351w questions?

I have a couple questions concerning the differences between the 351W blocks .

1 Are there any differences between 1969 and 1974 that you guys are aware of ?

2 What about any differences in bolt hole locations ?

Thanks Whitey

whitefield wrote: I have a couple questions concerning the  differences between the 351W blocks .

1 Are there any differences between 1969 and 1974 that you guys are aware of ?

2 What about any differences in bolt hole locations ?

Thanks Whitey

No differences in bolt hole locations.
1969 blocks are a slightly lower deck height, if I recall, they were like 9.480" deck, 70 and later were 9.5".
69-71 blocks are said to have the best iron composition (more alloy nickel in the iron) than later blocks, but don't know if anyone has ever actually done a metallurgy test between the various blocks.

I was hoping to have more input on this !

Here is what I ran into Friday night on my personal vehicle .( History first )I had 74 351w in the car for the last roughly 7 years and prior to that ran a 69 351w block out of a boat. Engine location mounts alternator location all the same as the 1974 351w.

Now here is what I found the alternator mounting holes that I was using are not there and the motor mount holes are located exactly 1 inch forward which moved the engine back 1 inch. Not complaining but never ran into this before ! Thanks

whitefield wrote:I was hoping to have more input on this !

Here is what I ran into Friday night on my personal vehicle .( History first )I had 74 351w in the car for the last roughly 7 years and prior to that ran a 69 351w block out of a boat. Engine location mounts alternator location all the same as the 1974 351w.

Now here is what I found  the alternator mounting holes that I was using are not there and the motor mount holes are located exactly 1 inch forward which moved the engine back 1 inch. Not complaining but never ran into this before ! Thanks

Since 1971, those blocks were not changed again until 1985, or so, when it now had a 1 piece rear main seal then 1993 when they became even thinner and had the hydraulic roller provisions added.

I have never seen motor mount mounting differences in any of them but, I guess a few must have been manufactured differently.
Alternator mounting holes in the block ...?

Alternator was mounted low and had a ( ear or tab ) that was threaded for the larger bolt and aluminum spacer to mount the alternator to . It Had a bracket that came of the water pump when I was running a mechanical water pump. When I went to the miezer electric pump I had to fab up some different bracket but still used the threaded 7/16 hole for the large alternator bolt and aluminum spacer and mounted low .

I have owned countless versions and year 351w but have never encountered anything like this with the motor mount bolt holes. Either way it was a learning experience!

I think I remember reading about some oddball Windsor's in like 1975 vans. It was something about a different intake bolt count though, I believe.

Some of them use a funky little bracket that bolted to the had and moved the alt. mounting a little lower and f orward and had the hole for the large alt. bolt. I'm not sure where I have seen this.