Where have other big bolts bought these two check valves or what have you upgraded to? These two go to the vacuum brake booster and two speed rear end to retain vacuum at low vacuum performance.
Most any parts place will have plastic check valves in stock from Dorman or other manufacturer. I ordered a GM one two weeks ago and thought it had the right fittings but it had 1/2” on one end and 1/4” on the other. Went to my parts house next morning and that what they had as well. I made bushings out of 1/4 hose and the 1/2” hose for snug over that. Replaced them both with those new checks and the shifting and braking works great.
