Hey, my Amazon had those holes!
Volvos engines have always been rock solid, but especially the old B18/B20 (Same engine, different bore) pushrods. I mean, you can take practically anyone of those old engines and rev them to 7500 RPM, stock. If I were to put a 16V header on mine I could go to 500 hp easy with just changing the rods and pistons, the only problem would be the yearly inspection.
And there are a couple of people who went the turbo-supercharged route aswell, there's an awesome looking opel Manta with a Volvo 2.3L 16V (B234) engine. https://www.pistonjuice.com/category/opel/manta/
Hehe, the garage... uh. Yeah, nsfw