Zen over on LRO has just fitted a lexux lump to a Rangie......
Difficult conversion, as there's no manual flywheel available, he had to have one custom made, amongst a host of other stuff....
I'd stick with the tries & trusted buick block...... TVR 5.0l Hybrid is what they used in the Bowler...... but for something DIY able, reliable and moderately owner freindly, I'd go for a 4.0l P38 lump, rip the management kit off it and go Mega-Squirt, with some 'mild' tuning, like say, high ratio roller rockers, stage 3 head, and a Hi-torque cam on TRV lifters, not Rhodes or solids.
a 'built' motor is as reliable as you build it, so really wouldn't matter too much where you start from, except that the 4.0l+ motors got bigger bearings....
Oh.... would have it relinered with top hats, and probably grooved for Wills rings if I was doing it, and if feeling 'flush' carrillo rods and some nice flat-top forged pistons, on lightened balenced crank. In which case, I'd possibly be persuaded to enlarge the bores a bit, and possibly go 'all the way' to 5.0l.
But get the bottom end right, and dont go too silly over the top and it should hold together no matter how much abuse you chuck at it......... well........
Standard bottom end, properly put together, should be reliable to around 7-8K rpm, with around 3-350 bhp turning it, add the carrillos and lightened toughened crank and foirged slugs, you can take that up to around 450bhp, and the same sort of revs.
Its competition references though, we're not talking 10K mile service intervals and a 250K mile 'life' like a proddy motor....
On stock bottom end, with 300ish, you are looking at 2000miles between oil changes, and rebuild after perhaps 20K miles.
Push the power up, and that starts dropping.
Use the competition rods and slugs and prepped crank, margin for safety increases, and you could possibly push rebuild out to 30K miles.
BUT, all depends on how hard you use the motor, and how you install it.
Devil is in the detail, and you need to pay as much attension to stuff like the radiator, oil cooler, remote filter adaptor and plumbing etc.
And of course the 'set up', ignition and timing........ worth a rolling road set-up, and 'concervative' fueling map.
