Vintage Mustang Forums banner

My 1989 351W block is not drilled for clutch pivot ball. Has anybody ever drilled and tapped a hole for one? (pic inside)

646 Views 11 Replies 5 Participants Last post by  dennis111
I have a 1989 351W that is not drilled for a clutch pivot ball. I was wondering if a hole could be drilled and tapped without destroying the block. Has anyone on this site ever done this before? It looks like there is enough space to drill and tap a hole but the area would need to be grinded level before I could drill and tap.

Would it hurt the block if I did this? Has anybody did this before on this site?


Automotive tire Bumper Chair Gas Wood
1 - 12 of 12 Posts

· Registered
Joined
·
8,166 Posts
You can get one of these:


Or here's a post where I used a different brand:

 

· Registered
Joined
·
1,173 Posts
My 65fb came to me with the one Lee posted on top, but I noticed the po had to grind a piece of the bracket for exhaust bolt clearance. I have bought the parts from the second link to replace it but have not done the conversion yet. For me it's going to be a much beter solution. kip
 

· Registered
Joined
·
8,166 Posts
My 65fb came to me with the one Lee posted on top, but I noticed the po had to grind a piece of the bracket for exhaust bolt clearance. I have bought the parts from the second link to replace it but have not done the conversion yet. For me it's going to be a much beter solution. kip
I had to grind part of the first one to allow the header on that side to clear. No major surgery was required...I just ground some off and sprayed it with some black paint. I just didn't like how it didn't allow the z-bar to be perpendicular to frame bracket which could have lead to some issues later on.
 

· Registered
Joined
·
1,173 Posts
I don't believe I can remove the upper exhaust bolt where the exhaust manifold attaches to the down pipe without removing the add on bracket, as well as the alignment concerns you mentioned. kip
 
  • Like
Reactions: Russstang

· Registered
Joined
·
489 Posts
Discussion Starter · #7 ·
I had to grind part of the first one to allow the header on that side to clear. No major surgery was required...I just ground some off and sprayed it with some black paint. I just didn't like how it didn't allow the z-bar to be perpendicular to frame bracket which could have lead to some issues later on.
I have read about how those bolt on z bar brackets do not mount the zbar perpendicular with the frame side and that is why I am looking to drill and tap a hole.
 

· Registered
Joined
·
8,166 Posts
I have read about how those bolt on z bar brackets do not mount the zbar perpendicular with the frame side and that is why I am looking to drill and tap a hole.
That's why I prefer the Wild Horses 4X4 bracket. It can be shifted both forward or backward to get the z-bar perpendicular. I don't know about the block you're using, but I put mine on a 98 Explorer 302 block because there is not enough metal in the correct spot to drill and tap a hole for the clutch pivot.
 

· Registered
Joined
·
1,498 Posts
I have a 1989 351W that is not drilled for a clutch pivot ball. I was wondering if a hole could be drilled and tapped without destroying the block. Has anyone on this site ever done this before? It looks like there is enough space to drill and tap a hole but the area would need to be grinded level before I could drill and tap.

Would it hurt the block if I did this? Has anybody did this before on this site?
I've done it in the past with no issues on a NOS 1989 block I got off ebay. I copied the location from an early block, drilled and tapped the boss, then made the area flat. It really wasn't a big deal to do.
 

· Registered
Joined
·
489 Posts
Discussion Starter · #10 ·
That's why I prefer the Wild Horses 4X4 bracket. It can be shifted both forward or backward to get the z-bar perpendicular. I don't know about the block you're using, but I put mine on a 98 Explorer 302 block because there is not enough metal in the correct spot to drill and tap a hole for the clutch pivot.
Yeah that Wild Horses EFI clutch pivot bracket looks like a really nice and simple setup. I am going to buy one just in case I need it. Thanks for posting that info!
 

· Registered
Joined
·
489 Posts
Discussion Starter · #11 ·
I've done it in the past with no issues on a NOS 1989 block I got off ebay. I copied the location from an early block, drilled and tapped the boss, then made the area flat. It really wasn't a big deal to do.
That is good to know! I also have a 1969 351W that came out of a manual shift Mustang and it still has the clutch pivot ball located on the block. I can use that engine and measure where I need to make my hole to drill and tap. It looks like the blank area on the 1989 351W block I have has enough room to locate the hole. I will measure it tomorrow.
 

· Registered
Joined
·
1,498 Posts
That is good to know! I also have a 1969 351W that came out of a manual shift Mustang and it still has the clutch pivot ball located on the block. I can use that engine and measure where I need to make my hole to drill and tap. It looks like the blank area on the 1989 351W block I have has enough room to locate the hole. I will measure it tomorrow.
Hey, you got this and it's a slam dunk! Since the 89' clutch boss is slightly different in outer appearance, I'd also consider taking measurements from other know fixed points (such as the bellhousing attaching flange and perhaps the oil pan flange) before committing to the drilling. I suggest this because I did the same and the hole ended up being offset somewhat on the casting (but still had plenty of meat.) Drill at a slower speed and use oil as a lube. You only need to drill deep enough to match the thread length of the pivot (with a washer.)

PS: My understanding is that the later 351w block continued to have that z bar boss cast into so that it could still be used as a replacement for damaged motors in earlier commercial truck motors that had manual transmissions. The 302 block didn't get that same thought when it was recast to be lighter.
 
1 - 12 of 12 Posts
Top