200tdi vs V8 chassis - different?

Evening all.

I'm looking to rebuild my Defender as a V8 but am unsure which new chassis to go for. The vehicle that is being rebuilt was originally a 200tdi that was then changed to a 300tdi from a disco at some point before I purchased it in 2003.

I've enquired with a local chassis stockist and they told me that the 200tdi/TD chassis has the mounts in the same place as the V8 chassis. If this is true, why then do all the chassis manufacturer list a V8 chassis option separate to the 200tdi? My main concern is being able to mount the engine and gearbox without having to cut/adjust the chassis mounts or bulkhead in any way.

Any advice on the differences between the 200tdi and V8 chassis would be much appreciated.

Engine mounts are in a completely different place. Gearbox mounts are different but the holes in the chassis are there on all of them so you just need the right mounts to bolt on.