996.2 head part numbers / interchange

Hey knowledgeable Rennlisters, I have a cracked bank 2 (cyl 4-6) head on my 3.6 (M96/03). I'm looking for a replacement, and there seems to be a number of revisions of the head itself. The base part for the head (which must be mated with the valve cover and cam caps, which are packaged as a separate part # together from the factory) is stamped 996 104 173 8R on my head. I've seen a bunch of similar part # heads for sale online, but some are marked 5R, 7R, and some of the online Porsche dealerships list parts DR/FR (which I assume is bank 1 or 2, and not helpful) Does anyone know if these are revision numbers, and if so, if there are any compatible parts / known incompatibilities between these variations? My engine is a > 66309951 revision, if relevant. (Crack is in the secondary air passage/coolant jacket, and is deemed not repairable short of filling the SAI passage - Len Hoffmann suggested this can be done, but I'd like to keep it emissions legal if feasible)

The last time I checked, a factory head (including valves and springs) was about $3,400 US. Take your VIN to the dealer, they will know exactly what to sell you. I would buy that all ready to go head from a dealer and not mess with anything else.

Thanks for the feedback, @yelcab ! Heads are about $4700 these days (inflation!), and I know the specific part I need new - I'd just rather buy used! For clarity, this is a track rat car with 160k miles on it and will likely to continue to have occasional failures; it's not a concours specimen It's simply not worth purchasing a full new head for the vehicle, when so many used alternatives are readily available. Heads are generally quite interchangeable between these vehicles - for example, many M97 (997.1/ some 987) heads can be easily re-plumbed to work on an M96/03 motor, by tweaking the AOS piping a bit. However, that would best be done by swapping both heads, which I'd also prefer to avoid. I know Jake has accumulated a decent matrix of compatible interchange parts (which he rightfully ought to charge to share!), and I was hoping someone would have similar information to share, as many have been down this path. I'd prefer to widen my search by including compatible parts that don't necessitate doing both banks, vs limiting to my specific variant. Cheers! M

Have u check with the dismantlers? I would guess DC Auto or LA Dismantler would have the single head u need or even a repairable core for a decent price.

On the 4-6 side just get a head that has 3.6 cast into it and 996 cast into it, don't pay any attention to the other casting numbers..minor differences but compatable...( as long as it's not x51 head, but easy to spot due to CNC ports)..

Thanks doc! That's exactly what I'd hoped to hear. I couldn't imagine anything significant changed, or it would be better documented somewhere. UOAS is hopefully part of this build, by the way, and looking forward to replacing my (still good!) Mantis sump with the new toy when you're shipping! (Cheers for the callout to the dismantlers as well, De Jeeper!)