Another timing curve question
I think my primary jets must be close, then. 14.5 to 15.5 AFR and no surging (at least up to 70+ mph cruise, 3600 rpm in 4th). I have yet to feel any surge/buck during steady-state, and light and moderate acceleration through the gears. (I'd thought I had 73 in there, not 70). Secondaries are still 85 (as far as I know!), no PV, but don't think I have even been into the secondaries very much. There is also a 50cc secondary pump.
It's pretty zippy for public streets :D I can floor it at 3000 rpm but can't stay on it very long because it's really coming up on the cam then!
So I won't do anything to the PVCR for now. I found a book online that says a 4780 originally had .069 PVCR. Next step is to drive it around with the 8.5 PV and see what the AFR is doing under more throttle and higher RPMs (will probably need a passenger to read the gauge).
Edited to add: 70 jets (.073) and .069 PVCRs calculate pretty close to the area of 85 secondary jets (.100). In fact those are the original specs for a 4780-2... Hoping not to have to change too much :)