The engine itself is fine. I have a 175hp tune on the vehicle; built with high lift cams, ported heads (in between a VHPD and a standard head). Titanium pistons, titanium crank, new liners etc. Engine is setup for 230+ w/ ITB's and a tune*.
Huge caveat on the tune side of things. These engines are great if they are dialed in before you get it.
The network in the US is very small - parts have to come from the UK. Ecu tuning is DTA, emerald, or other european oriented ecu. I'm sure you could get a haltech or something, but it would require a good amount of work to build a map.
Despite mine being off and on the road, when it runs, god is it something else.
Its the lighest engine, revs very high (if setup right), my cams come on power after 6k, and push all the way up to 9500. The engine really is a race horse - they run so well, but if it breaks a leg, it can be catastrophic.
Don't chase power etc, and you'll be fine. Don't be afraid to rev it.