318 LA rebuild after losing a valve seat

Timing may well be just fine.... your info on using the square to line up the dots is good news.

(FWIW, I CAN feel 4 degrees advance and have done the A-B test of that. It showed up in the off idle response and mid range.)

If you get curious: If you tape a degree wheel on the crank pulley, indexed it to a temporary pointer to 0 with #1 at TDC, and turned the crank to where you thought the intake was at it's peak opening, you will very probably know if you are in the ballpark or 14-15 degrees off. Here is a timing wheel you can print off and tape to some stiff cardboard: The Machinery Cleanery Universal Timing Disc, Degree Wheel, Downloadable - Goniometro per Messa in Fase dei Motori a 4 Tempi -