got news on the LWB Sierra!
i spoke to the guy who owns it. its standard 1.3L, stock head, pistons, and internals.
has approx 110HP at rear WHEELS!
it runs on straight LPG and does not use petrol, it has a complicated set up, using a supercharger off a toyota 4AGZE motor, through a mazda factory intercooler, internal wastegate, twin BOVs, electric thermo fan and electric water pump, and is running good at the moment.
they still want to do more work and refine the set up more. he said he's running at 8psi, but has had it at 24psi (but undrivable)
a complex set up that works. he doesn't wheel it much, more of a maller kinda thing. 33" all terrains, stock driveline.