Here are a few GM cam timings that might be helpful.

To calculate the proper tappet lift at which to measure the seat to seat duration for a solid lifter cam:
Divide the lash by the rocker ratio and add .004".

For the 097 cam below, the proper tappet lift to use is .012" (.012/1.5+.004). The actual seat to seat duration is 272º not the 287º Chevy claims. I've highlighted the proper tappet lift for the ones that fall in the table.
 
 

 Chevy 3736097 ( intake lobe )... Chevy advertised dur is 287 deg... lash @ .012.

                       Lobe Lift ,...... Duration......

                       .008 ____________ 288
                       .010 ____________ 278
                       .012 ____________ 272
                       .014 ____________ 267
                       .016 ____________ 264
                       .018 ____________ 261
                       .020 ____________ 258
                       .050 ____________ 228
                       ---------------------------------------------

                       GM 3849346 ( 30-30 Duntov ).Chevys advertised duration is 346... lash .030.

                       .008 ____________ 440
                       .010 ____________ 418
                       .012 ____________ 396
                       .014 ____________ 375
                       .016 ____________ 354
                       .018 ____________ 331
                       .020 ____________ 314
                       .050 ____________ 254
.024" is the proper tappet lift. It's not on the table. Further date points to the .024" duration being 304º.
                       ---------------------------------------------

                       Chevy 3925535 ( intake lobe ) L88 cam.Chevys advertised duration is 354,Lash .024 ??

                       .008 ____________ 395
                       .010 ____________ 374
                       .012 ____________ 353
                       .014 ____________ 336
                       .016 ____________ 324
                       .018 ____________ 316
                       .020 ____________ 309
                       .050 ____________ 264
                       ---------------------------------------------
 

-929 chevy cam

006" 253/264
           .050" 193/202
           .200" 96/105
           LCA 112
           Intake cl 107

---------------------
Chevy Hot Cam:
Hydraulic Roller
adv--dur________279/287
.050___________119.1/229.3
.100___________187.7/197
.200___________135.8/143.1
LSA___________112

--------------------

These are the only cams I have this data for. If you have others, please send what you have and I will post it.

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