When changing to the 351 head do I need to use the 351 or 302 pushrods ( I know that I need to use the bolt hole bushing-washer )?
also 351 windsors come with 1/2 inch head bolts and 302s come with 7/16 inch head bolts. Edelbrock makes those bushings for their own heads but will work with others also, then just use regular 302 bolts
You really need to check for proper valvetrain geometry. The 302 pushrods may work but it must be checked to be sure.