Major Ledfoot ^ Cheers.
I have an 89 B234 engine with a manual timing belt tensioner which I'm collecting from my mainland shed next week. When I get it home, I'll compare the 2 engines and see if an auto tensioner will fit on a manual tensioner engine - internet rumor says not, but there don't appear to be any extra holes in the later engines. So, we'll see.
A followup on the B234 Timing Belt Tensioner Question:
I've started to tear down the B234 with manual tensioner, which sat in a shed on the mainland for a long time.
It appears there's two different types of B234 block castings.
The early type of block isn't drilled for the automatic tensioner.
Also, the early-type B234 block doesn't have the 'bumps' on the oil galleries which one associates with the preperation for piston oil squirters on L-block B230 engines. The oil gallery side of the B234 resembles a K-block B230 in this respect.
Seems to me therefore that if there's L-block-style bumps on the exhaust-side oil gallery of a B234, it's a safe bet it will have an automatic (hydraulic) timing belt tensioner.