Master cylinder question

[lillwr]

I bought a 73 3/4 ton with a 350 that has obviously been pieced together. I bought a replacement master cyl. and went I went to swap them I noticed the old one was for a 454 but mounted to a booster belonging to a 350. Should I just put my new master cyl. on and hook the lines up accordingly?

The 454 has the larger bore line on the back whereas the 350 master cyl. has the larger bore line on the front

[lillwr]

I suppose if the rear line goes to the rear line on the proportioning valve and vise versa it doesn't matter, correct?

[ray_mcavoy]

The smaller diameter line (should be 3/16" OD) is the one that should go to the front brakes. And disc brakes are always plumbed into the end of the master cylinder that has the larger volume reservoir.

The larger diameter line (should be 1/4" OD) is the one that should go to the rear drum brakes. Should also correspond to the smaller reservoir on the master cylinder.

[lillwr]

Thanks. Thats what I figured but my roomate said it wouldn't work because the bowls are opposite on each unit. I said it didn't matter because you just put the front line to the larger bowl and the rear line to the smaller bowl as you stated. The old cylinder didn't belong on this truck to begin with. I now have the correct part and will just put the correct line to it's corresponding hole which is larger goes to rear and smaller goes to front