Hello, I have a 68 Firebird with conversion to power disc front and drums brakes in rear. My master was weeping and now failed. Since the mc was leaking it ruined the plating finish on the booster so I was contemplating replacing it with a combo master and booster, but noticed that there is an option for 9" or 11" booster. Currently I have the combo mc with 11" booster identical to the one listed here on Jegs Jegs Combo Brake MC and Booster, but wondering if a 68 could have come with a 9" booster and kind of like the idea of regaining a little bit of engine bay real-estate . I just wanted to keep it as close to original as possible and also wasn't sure if a 9" booster would affect braking performance or not. I don't think it will and beleive the proportioning valve is identical on both. I appreciate any thoughts or experience from any of the forum members!

Honestly would keep your original booster if it works.
Parts these days are garbage, those 9" boosters are not as good as what you have now.

Thanks, I agree... quality replacement parts for these classics are hard to come by. The current combo mc/brake booster I have now came from one of the bigger name in the disc conversion market and master started seeping within the first year. I will admit that moving from all manual drum brakes to power disc/drum was a significant improvement that I never regretted!

I’m running a Tuff Stuff dual 9” booster. High quality. Check them out.

My 68 with 4 piston front discs was manual. I purchased a booster on Ebay, and it has performed very nicely. $105

I'll post the pic of the sale