What do you mean by reverse staggered?
Tomei (For want of a different option) offer the following:
Poncam A :260 inlet and 252 exhaust at 9.15mm lift.
Poncam B: 260 inlet and 260 exhaust at 9.15mm lift.
I have a 256 inlet and a 252 exhaust.
Upgrade option on the inlet side appear to be to go an extra 4 degrees and more lift picking one of 9.15, 10.25 and 10.80.
On the exhaust side the increments are in four degrees also although I didn’t look at the lift.
Inlet 256 degree 9.25mm lift. Opens TDC. Closes 41 degrees ABDC. For 221 degrees duration at 50 thou valve lift.
Inlet 260 degrees 9.15mm lift. Opens 1 degree ATDC. Closes 43 degrees ABDC. For 222 degrees duration at 50 thou valve lift.
Inlet 260 degrees 10.25 lift. Opens TDC. Closes 43 degrees ABDC for 223 degrees duration at 50 thou valve lift.
Inlet 260 degrees 10.80 lift. Opens 1 degree BTDC. Closes 41 degrees ABDC for 222 degrees duration at 50 thou valve lift.
Exhaust 252 degrees 9.15mm lift. Opens 42 degrees BBDC. Closes 8 degrees BTDC for 214 degrees duration at 50 thou valve lift.
Exhaust 256 degrees 9.25mm lift. Opens 46 degrees BBDC. Closes 7 degrees BTDC for 219 degrees duration at 50 thou valve lift.
Exhaust 260 degrees 9.15mm lift. Opens 47 degrees BBDC. Closes 3 degrees BTDC for 224 degrees duration at 50 thou valve lift.