I agree with Grant. Some will interchange depending on the cc volume. There are a several listed on mortec that are shared by 305's & 350's. Not too likely you have a regular set of heads with 2.02 valves.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine