The 510 Realm

I was told by some Datsuners that I could improve my braking by installing a 1 inch brake master cylinder.
I purchased one through datsuns.com?
Doing some more online reading, I also read that I might experience a hard pedal with a 1 inch MC.
I do not believe I have any room for a brake booster with my VG30 engine.
I have smaller Wilwoods on the front and drums on the back.
Can anyone give me any advice? Thanks!

I have the 15/16 master with 280zx front brakes and aluminum rear drums and the pedal is waaaay too firm. I am after the 7/8 master as that should minimize the firm feeling. I cannot comment on your exact setup, but I have a feeling that you'll experience a similar pedal feel.

I have 15/16 on my wagon without a booster. I don't like boosted brakes. The pedal is pretty firm but it doesn't bother me. I have a rear disc conversion on it and s12 fronts if that matters to you.

The size of the master does not improve the braking unless you have some huge calipers and need to move more fluid. I have the 7/8 with wilwood 4 pistons on all 4 corners and it is just about perfect in my opinion.

The smaller diameter boosters are from a 610/710/S10 and B-210. The 620 is also small. The problem is fitting it beside the clutch master. I have the 15/16" on a 710 with it's booster with '84 Maxima struts. The braking is superb. The diaphragm is 6" so the outer case is at least this diameter.

The vacuum booster decreases your pedal effort about 50%. A 132 pound pedal pressure produces about 1,000 PSI line pressure without vacuum. (I've lifted my ass off the seat before applying the brake so this is easily attained) With vacuum it's 1,550 PSI. To achieve 1,000 PSI with vacuum only 66 pounds of pedal pressure is required. All a booster does is reduce your input level and at one time I said the same thing but reducing long term driving fatigue in stop and go or racing is important. The 510 and the 1200 are light enough to not need a booster but all cars after were getting heavier and heavier.

I'm going to go with it boils down to how it feels/works for you personally. I do not like boosted brakes. They feel.... mushy? Last year I did a 4 wheel drum to 4 wheel disc conversion on my 1970 Challenger. No booster on it either and I'm VERY happy with how they feel and work. HEAVY car compared to a 510. I have a 620 I'm considering taking the booster off of because I just don't like how the brakes feel compared to my 510 or my Challenger. I'm waiting on that one though as I just converted the front brakes to hardbody calipers/pads/rotors. I figure I should drive it first before I make that decision.

This is all opinion. YMMV. Have fun. Do what works best for you.