I have an Autometer analog style afr guage, with the sensor fitted to a spigot welded into the lcb collector just forward of the gear shift where the floor tunnel widens.
I'd recommend the afr meter for anyone using a weber/dellorto - these are complex carbs with four (five if you count the cold start) fuel metering stages/circuits that need to work in harmony. Being able to watch what is actually going on with the afr is really useful (and sometimes quite different to what is taken as gospel). There are thousands of potential combinations of jets, correctors, venturi, valves and correctors - the chances of guessing the right ones, or that someone else has exactly the same specs that you need are virtually zero. And dyno operators are working in a highly controlled environment which cannot really factor in driving style. With some patience and a bag of jets etc (which could cost you $200) you can save yourself heaps of fuel, grief and embarrassment. The A-series is never going to run like a swiss watch (although maybe one of GR's new cranks would do the job) but it doesn't have to be a tractor either
Think about a good fuel pump, pressure regulator and guage as well. my 45 likes 2.8lbs/inch, but people use anything from 1.5 to 4.00 - getting the afr and pressure right can let you run a more aggressive cam and still live with it in traffic. I have an Autometer jobbie for that as well -which showed me the Carter pump I was using was losing up to 3 lbs pressure under acceleration! Fitted a Facet Red Top - problem solved. Also discovered my long serving Redline regulator was 1.5lbs out... Some regs have a lag period that can worsen the 'hole' in acceleration, but if you don't have a meter to let you know, you can be chasing all sorts of possible causes, when you could be just enjoying the drive.
