Dang thanks for the information this is huge. I need this k24a, I was reading about it but the r40 was confusing me. Hit me up on my ig with pic if you could please.
So I bought a 2006 si complete donor car for my cb7 sedan getting my mounts from Hasport but they recommended that I would hate driving it with this swap I did get the car only 2200 the heads are bad but should I just invest in get a k24 bottom or build the z3 and not spend more money and just investing in the z3?
Depending on how bad the z3 is and how many miles and abuse it got. Would definitely determine your route. On fully spending the money on the head and block or k24. I would get the k24 block swap everything over from the z3 like oil cooler and spend the money on the z3 head. K24a are cheaper to source if you ever ran into issues vs the z3.
And for the hasport mounts, try and get a soft bushing like 62A to minimize the vibration. Also, look into other companies like innovative mounts to see if it is a better option for your build.