My thoughts?? YOUR HARD HEADED!
Listen to Zip and what the others have been telling you.
Gezz man, what part of this dont you understand???
"The valve springs recommended for the cam you have is P/N 943-16. these springs have a seat pressure rating of 240 lbs @ 1.900 installed height and a coil bind of 1.180.
I looked up you cam at Comp Cams (12-900-9) (288A-R6) and these were the recommended springs."
Using cheap valves & weak springs is a recipe for disaster with a solid roller.
JMO, CP