Went back through some old threads and, of course, @hookem posted the drill bit size like the professional that he is. It's a 17mm (or about 43/64). I put my calipers on the old HB rod and compared to the new and the new is definitely just slightly smaller in diameter than the old so I'll open it up just a hair.

 

Just put it in. It will work. Slight design difference. I’m told if you get for exactly a 2011 the rod hole will be the same. Just a note.

 

I ordered mine from Rock Auto for a 2011 LML and the hole was just slightly smaller than the original off the truck. I just used a Dremel and made them match. Haven't finished putting it back together yet since the Dorman power steering cooler I picked up needs some modifications to fit. Should have it wrapped up in the morning.

P.S. for anyone reading this in the future. Getting that clip back on the brake pedal switch can be tough. I used a zip tie around the switch and pedal arm to hold the switch as far on the pin as it would go and that made it easy as can be. Just don't go crazy tightening up the zip tie. Don't want to damage the switch.

 

I also just bought a 2011 LML Hydroboost (p/n 19371361), for my 2005 LLY.

1. Would there be any benefit of upgrading the Master Cylinder to the 2011 LML version, or would it be the same as the original LLY Master Cylinder?

Either way I would like to put in a new MC while I am doing HB upgrade, new PSC steering gear box and PSC power steering pump, and PS lines.

2. The clip that holds the HB rod to the pedal arm is mentioned earlier. Would it be a good idea to replace it as well?
Does anyone know the part number?

3. Does anyone have any other parts upgrade/replacement suggestions to do while upgrading the Hydroboost and Power Steering?

Thank y’all for all your advice and suggestions!

 

Retainer clip for the rod to pedal arm is
15048329
I bought mine on Amazon, although the price is now more than twice what I paid 4 years ago. Naturally!

I was unable to remove the old clip without destroying it. Some others did better than me. I didn't change the master cylinder, so I can't address that. The HB made a noticeable improvement on mine.

 

Retainer clip for the rod to pedal arm is
15048329
I bought mine on Amazon, although the price is now more than twice what I paid 4 years ago. Naturally!

I was unable to remove the old clip without destroying it. Some others did better than me. I didn't change the master cylinder, so I can't address that. The HB made a noticeable improvement on mine.

Thank you! I really appreciate this clip information. I have a feeling that I will likely break the clip as well.