I have no way of telling any differnt? WRONG.. I have a sun DGA1800. And yeah any open loop mixer based system will never be perfect, but no less perfect than a set of SUs. You can mess about with scopes, and sensor reading till you are blue in your face, the final truth is always in the composition of the exhaust gases.
As for the blocks, I've never had one in a classic fail, but the P38a is dreadful. Interesting your comments infered about Bosch L-Jetronic, which after K-Jetronic remains the most reliable fuel injection Bosch has ever made.
When I bought my reliability disaster block munching liner slipping 3.9 LPG converted classic, my dad bought a 300TDi disco. During that time the rangie has done twice the millage and never once failed to start and complete trip, and brought the disco home twice, each time due to terminal engine failure.