I need to put a new head on my '94 940 B230FB. The LPG has finally eroded the valve seats beyond adjustment, not too bad at 200K mi, quite a few don't make even that.

It currently has a 531 head. I can get another head (I think it's a 389, not sure what engine it was meant for), fully built up, brand new, new old stock, still in its original Volvo box, for a lot less than a rebuild of the original head would cost me. So I'm turning to those more experienced with B230 engine rebuilding for advice:

1- would I be OK in putting that on, or do I really need to find another 531 head or rebuild my own? This is of course supposing it has no injector holes and a compatible mount for the rear-of-head distributor. Considering the age of the head it's very well possible it's mean for some kind of B21/B23 variant

2- Would I need to transfer my own cam or would I be OK or even better off using the cam that's on that head? (or would that depend on what cam turns out to be in there?) (

2a- If swapping is needed, can I just swap the cams or would I need to swap or renew the bearing shells as well?

3- Will it play nice with the fuel injection and ignition or will I need to change/adjust those too?

Thanks,

Bram