Low Mount Power Steering Pump - Drill the Block?

303Radar

Well Known Member
Supporting Member 2
I think the answer has been posted, but I can't find it using the search.

To use a low mount power steering bracket, do I need to drill the block? For reference, here is a picture from Allan Grove:
http://www.alangrovecomponents.com/images/New_Images/Large/421L.jpg

What I can't seem to find information for is how deep can/should I go?
After taking my umpteen'th look at the picture, I'm curious if the bolts on the water pump are spaced correctly or can I re-drill the rear plate?
If so, where could I find studs to hold the pump in place and mount the Allan Grove bracket to?

I guess an answer to either question would be good.

Thanks!
 

303Radar

Well Known Member
Supporting Member 2
Thanks Don!
How deep is it safe to drill? I'm guessing an inch is good but not sure that would give enough threads without a special tap.
Is this safe to do myself?
 

nana1962409

Well Known Member
Supporting Member 2
I measured the bolt hole depth in a couple of my blocks and they are between 1.010-1.100 deep. If you wanted to drill it yourself I could probably make a template off one of my blocks if you needed.
 

303Radar

Well Known Member
Supporting Member 2
I measured the bolt hole depth in a couple of my blocks and they are between 1.010-1.100 deep. If you wanted to drill it yourself I could probably make a template off one of my blocks if you needed.
Thanks for the offer! Since I have the Allan Grove bracket already, I should be good to go.
Bottoming tap?
I think a bottoming tap is in order. I've never heard of one and had to Google it. Now to find the right size and order it.

Thanks everyone!
 

303Radar

Well Known Member
Supporting Member 2
In case anyone needs a part number for a 3/8th 16 thread bottoming tap, here is the p/n from Home Depot:
1003270087 - https://www.homedepot.com/p/Drill-A...0:0}++1003270087+{productkey}+qu:{1003270087}

I am a bit concerned because the description almost makes it sound like a left handed/reverse thread. However, when I looked up the part in the Drill America catalog, it didn't mention anything about reverse thread.
http://drillamerica.net/content/catalog17.pdf

I figure for $7, I've spent more on wrong parts/tools before.
 

303Radar

Well Known Member
Supporting Member 2
One last question.
I was looking at my current 3/8ths tap and it to use drill 6/16ths. Wouldn't I want to use a slightly smaller diameter bit than the size of the tap? Say 5/16ths?
 

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63 dream'n

Well Seasoned Member
Supporting Member 4
I sure would think on the instructions they would list the fact that some 409-348 blocks were not drilled and would include the depth measurement for doing so.......I know I’ve seen that measurement previously whether that was on a billet specialties true track instruction kit or on a power steering or low mount alternator kit that information is out there
 

303Radar

Well Known Member
Supporting Member 2
If I had had a little more foresight, I would've asked when I placed the order.
I'm also sure if I called and asked, it would be like talking to Don or Phil. I'd get a knowledgeable answer right away.
Thanks again everyone!
 
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