Thanks for advice. The reason I'm asking because back in 1991 I had a very nice, all-custom stroker engine in my 2WD Sapphire. IIRC, ~90mm crank in a re-sleeved YBD block with ~94mm bore. It could spool an RS500 T04 like there's no tomorrow, but unfortunately it wasn't very long lived due to combination of extreme rod angles, very flat pistons and the limitations of the block itself. I stayed with stock displacement bottom ends with the Sapphire 4x4 and the Escort the following years but sort-of gave up on Cossies in '94 when the 4x4 was stolen and I finally sold the Escort.

Now that the "tribute car" 3dr RS500 replica is in the planning stage, all I really want from the engine is a massive midrange. Even more than the 2WD had, with a modern turbo. I don't care for a high-rpm screamer. A budget of 15k doesn't sound impossible at all.

I've just been wondering if someone, somewhere has already built a very large displacement turbo YB. There's no point in re-inventing the wheel, so an experienced YB engine builder might be the best way forward if 2.5l+(++) isn't common knowledge.

OTOH, the "smart" (read: cost-effective) move would be to use a completely different engine, a modern VVT/VCT 4-cyl like 2.0/2.3l Ecoboost stroked out to 2.6l (Esslinger) or even a V6, but the distinctive red cam cover is such a huge part of nostalgia that I'd hate to give up on the YB.