Thanks for the feedback.
I just double-checked and in Espgaluda changing h.active from 450 to 448 definitely wipes 2 lines off the top of the image.
I tested Garegga in 320×240 optim with h.samplerate 432 and the image is completely scrambled. It looks perfect in 512×240 optim. What about the board makes you think 320×240 would be better than 512×240? I don’t have a good understanding of the difference in this context.
6750000 / ( 263 × 59.37 ) = 432.295
I’d like to do Raiden next. Is there a way to eliminate any of these frequencies or do I need to test with each of them:
XTALs: 20MHz, 14.31818MHz, 12MHz
CPUs: 2 x Sony CXQ70116P-10 (NEC V30 @ 10MHz), Z80A