E30 Zone

So on realoem these things have the same part no. for both M52 and M54 engines. However, the M54 ones look slightly longer. So I got out the calipers and measured all 48 valve springs and it seems that the M54 ones are all indeed around 3mm longer than the M52 ones! Any likely reason for this? Could it be that the M52 ones are tired and no longer return to their full length?

It may be that the M52 spring is compressed more than the M54

I suppose in that case I'm best matching springs to cam? I.e. m54 springs for m54 inlet cam and m52 springs for the exhaust cam. Or would it not really matter?

Whilst on the subject of valvetrain, when I took the M54 to pieces I dismantled, cleaned, bled and reassembled all 24 lifters. I kept the intake ones matched to the cam lobes as I'll be using that cam, but is there any reason why I can't use the other 12 ready-serviced lifters on the exhaust side? Or am I better using the M52 ones keeping them matched to their respective lobes on the exhaust cam?

Id just use the tallest springs, I wouldn't be worried about mixing the lifters up either, using the newest/lowest milage parts is always the best way to go

Thanks mate, I was hoping that's the correct strategy, it's what I've been trying to do