Valve preference SI vs. Manley

[shawburn]

I am looking at buying a new set of aluminum heads. The company I am looking to purchase from sells assemblies with SI severe duty valves. I have always run Manley's severe duty valves. What are engine builders thoughts on SI compared to Manley? Should I purchase the heads bare and get Manley valves? Thanks

[hogracer3d]

both of them are high end imported valves, I think.
I have run SI for several years, without any problems

[parrot69777]

I always buy bare heads and then assemble myself. Most all valves are made by one or two companies anymore. Then put into the individual boxs for resale.