View Full Version : Block mount locations?


dotstereo
12-05-2006, 02:31 PM
Ok guys, I know it's a dumb question, but sometimes the simplest answers are the hardest to understand (and I did search).

Most everyone uses the same 4 holes (I've also heard these referred to as 'boss mounts') on the block for the motor mounts, but there look to be 2 more holes on the block next to the first 4.
Can these be used in conjuction with the other holes? (I need the mounts to sit further back on the block).

Here is a picture I marked. The holes I'm asking about are the ones on the far right.

http://img366.imageshack.us/img366/3952/bosslocationmn3.jpg
Thanks a lot for the help.

Ted J
12-05-2006, 02:49 PM
Ok guys, I know it's a dumb question, but sometimes the simplest answers are the hardest to understand (and I did search).

Most everyone uses the same 4 holes (I've also heard these referred to as 'boss mounts') on the block for the motor mounts, but there look to be 2 more holes on the block next to the first 4.
Can these be used in conjuction with the other holes? (I need the mounts to sit further back on the block).

Here is a picture I marked. The holes I'm asking about are the ones on the far right.

http://img366.imageshack.us/img366/3952/bosslocationmn3.jpg
Thanks a lot for the help.

I wouldn't suggest using them. If you look at the holes on the right they don't have the triangular shaped braces on the side casted into them. That would be by better safe than sorry guess though.

'JustDreamin'
12-05-2006, 04:33 PM
Also, not all blocks have that set of holes (most iron blocks) which is another reason why most people don't use them.

As mentioned above, there isn't the level of bracing / webbing on the rear bolt holes, which probably means they're not as stout. But, if you need to move the mounts rearward, I would suggest you pick up all 6 bolt holes (with a piece of flat plate). That would probably be overkill, but I'd rather err on that side than the other.

'JustDreamin'

bczee
12-05-2006, 05:40 PM
I have heard that some sand rail people have used the rear mounting holes. maybe utilizing all six ?? but I guess it can be used...

Ted J
12-05-2006, 09:52 PM
Another thing to factor in is that on the passengers side the starter is right in the way of those holes.

dotstereo
12-06-2006, 01:51 AM
Another thing to factor in is that on the passengers side the starter is right in the way of those holes.

After looking at more Ls1 blocks (its hard to find pictures of the passenger side) there is only a fifth hole anyway. The sixth hole (on the bottom) is only on the driver's side.

Here is a pic that shows what I'm talking about:

http://img78.imageshack.us/img78/8125/d5d43fe8.jpg
Thanks to everyone's help.