1.5 versus 1.6 Rockers

I bought 1.5 rockers and am reconsidering seeing if I can return them for 1.6 . Using DynoSim6 to see the possible difference, with a 508", 10.5 to 1, 850 carb (I may go bigger later), these are the differences. Probably not worth the hassle and added cost of the return for a primarily street, occasional strip car?

I always use higher ratio if starting with new setup...

Thanks Brian!

If the cam is smaller than optimum, they (almost) always help.
If the cam is too big it gets worse.

Generally, on higher ratio intake rockers help, the exhaust doesn't need more lift (better: earlier opening).

It will change valve geometry some, moving the pushrod angle outbd possibly requiring some head clearance.

I don't trust that series of simulation programs to give realistic results any longer... FWIW

Rocker ratio should be selected in conjunction with cam profiles, LSA, etc. That said, my personal experience has been anywhere from no improvements found to maybe 5-8 HP on "best case" scenario.

The other thing is you can't ASSume the published ratios reflect the actual delivered (real valve springs, not checking) ratio. It can also vary a good bit from above to below stated ratio depending upon brand / design. It's one of those areas that the only way to know is to mock up everything with the actual parts and check the net lift.

this.