I have tried K-Motion K-700 springs (120 @ 1.700) and the Comp Cams 941-16 (130 @ 1.750) and they both work well. I had the comp springs in at 1.700 and they seemed to do the trick with the Sherman Lifters. I ran some more lash than you so that could be something to try.I never spun my engine as high as your trying to so that could be an issue as well. 7200 max. The only time it floated the valves is when I went to a smaller tire and it tried to go through higher. I never had titanium retainers and the springs were wipped at that time so it was an unfair test. Im not a firm believer in the bee hive springs yet but im kinda thinking that they are ok if you are trying to keep the valve train weight down. Id go back to basics and just order a set of 941's and jam them in. 7500 shouldnt be a problem with 140 on the seat. Are you running EOS in your oil? Probably a good idea with big spring pressure like that. I ran the Valvoline "not for street use" 20w50...6 quarts+1 EOS and never had an issue.Camshaft was MINT when I pulled it and so were the lifters.
PS...I miss my Vortec
