02 E53 3.0i Lifter question

[omgwtf]

Greetings,

I'm in the process of replacing my 02 X5 E53 3.0i M54 head, and when re-installing the lifters I noticed that there are 4 different types of lifters on the the exhaust side.
I checked my donor "head", and all of lifters are the same both sides int & exh.

I was was wondering if anyone has come across this and do I need to match them all.
I have attached images.

Thanks for your time.

[crystalworks]

I believe they are all supposed to be the same... The 3 I've done all were, though those were M50/M52's.

https://www.ecstuning.com/ES22497/?g...FQQpaQodEw0Ofg

Edit: They do have a revised/superseded part number though. Perhaps your head has a mix of the old and new lifters?

[omgwtf]

Thanks Crystalworks,

I only had 4 on the exhaust. I figured that the donor head would too, but was mistaken.

More concerned that if they need to go in a specific location or where ever.

Thanks again

[crystalworks]

No problem.

I think it's good general practice to put them back in where they came out of... but I'm not sure how absolutely necessary it is. I usually number them from front to back with a sharpie after wiping them down.