3Y and 4Y head difference

[sirsprinter]

i have fears i have a dodgy 4y head

is it possible to put the 3y head on, as sourcing a 2nd hand 4y head is much more expensive and harder to come by?

thanks in advance

[Dazza]

The water passages are in different places. I have put a 4Y head on my 3Y. I just had to use a 4Y headgasket. 3Y heads changed about mid 1986 and you have to use a different headgasket from late to early heads. Early 3Y heads have smaller inlet ports. You should be able to use a 3Y head as long as you use the correct headgasket for it and make sure the water passages line up.