From a 4R1 parts book 2 of 8B313 head gaskets. You will also need 8 of 6B6225 and 8 of 7B2419 seal rings for water directors. Take note of where the directors are aimed to put them back correctly.
There could be changes for your serial number so I hope someone else with the correct book can confirm.
I don't have a 4r or 5r so not sure where the oil supply to the top end went, could be external pipe.Some models had a couple of extra seals in the head gasket for oil supply lines.
Two heads will be more managable than an 8U 9U one piece they are a crane job if you are on your own. Not a lot of light parts on any of them.
enjoy
I got an aftermarket set for one 5 years back will look for the part number for you, regards Andrew
Thanks guys