I think Dan means the main bearing cap bolts?
Yeah deffinately agree with Giorgio on the blueprinting front. Unfortunately, blueprinting is an expensive business due to the labour involved. Lots of measuring both dimensionally and in mass, plus assembling components and setting up on different machines to perform the neccessary machining.
A full balance of the crank assembly, c/w front pulley, flywheel and clutch cover all attatched is rarely done but is pretty much the ultimate in dynamic balancing.
All this machining work will cost a lot of money and TBH, I doubt you will notice much difference unless previously the engine was mechanically tired.
It is all relative to how your engine was before the build. Tolerances on old car engines were fairly poor by comparison of todays cars. Blueprinting is nothing more than optimising the standard components, allowing us to get the very best out of them. Whilst 130 bhp is probably possible on a completely standard G40, it'd take a lot of effort and money/time to do it.
If it were my money building a relatively standard engine, I'd just go for the hone (and deck if required) on the block, new rings/bearings/thrusts/bolts etc, reface the flywheel and a dynamic balance. Add a new oil pump and the job's done.