[924Sman]

Definetly a late engine, whether it is an 88 or not? Should run a higher compression than an 87, try a compression check or put a scope in a cylinder and check for a dimple on the piston head face. If flat may have an 88 or euro pistons. If there is a dimple and 2 valve slots it is an 87 or<.
Engine number I found best seen from the pass. side looking str8 down over the speed and reference sensors.

I was reading a while ago about some owners replaced the spring tensioner for the essentric roller for ease in belt tensioing and weight. I say weight as the people were racers that were in the discussion. This could be a case here. PO decided to go the cheap route when it was thought they needed a new tensioner for what ever reason.

As far as the ISV hold down bracket goes mine broke too. Very brittle rubber. So I tie wrapped mine down and works fine.

Dal