Oil change - will this cause issues?

[slappy]

Those were the good old days, I had a beige coloured mk2 Cortina that never had an oil change in 20,000 miles, when the gearbox gave up the ghost I fitted one from a mk1 Cortina that meant I had to cut another hole in the transmission tunnel as the gearstick was now in a different position.
I gave the Cortina to my older brother for free, he did another 10,000 miles in it with no oil change before he wrote it off.