After fiddling for over a year with those irritating flat spots on the Weber, I finally made the decision to go with a rebuilt set of SU HS6 carbs for my 1970 142S. The performance is FAR superior. While I miss the benefits of having an accelerator pump on cold Colorado mornings, the SU setup has two chokes. In addition, I installed an OEM block heater that makes cold start-up a snap.

Having now owned three Volvos over the past eight years with three different carb set-ups, here are my thoughts along with the cars I've owned:

SU (62 P1800 and 70 142)--Top performance, easy to adjust mixture, flagship Volvo carburetor, solid reliability so long as they are clean and in tune

Stromberg (68 144)--Smooth idle, that darned diaphragm!!, funky "allen wrench" tool needed to adjust mixture, reliability issues, harder to start in winter time

Weber (70 142)--Easy to adjust mix and idle, accelerator pump, parts are easy to find, FLAT SPOTS!, electric choke is brutal, hard to find just the right needle size

I'm sure others can add more details regarding the pros and cons. Thanks to Jeff Palya at Paltech for supplying the new SU setup.

Luis
1970 142S