Gus, the 48IDA's will work well on a 402.

There are some initial baseline jet setting listed in Pat Braden's Weber book I believe. I highly recommend this book, available on Amazon. It explains the operation of IDA's in simple and understandable terms. It's not just jet setting to get right - it's also chokes and the particular configuration of 48IDA. Not all 48IDA's are the same, they vary dramatically in terms of the progression holes drilled in the throats. To get your 402 to run right you have to have matching IDA's (same progression holes) with the right size and spacing of the progression holes.

Webers get a bad name because people a) don't have matching sets, b) have the wrong set within the family (again, not all 48 IDA's are the same), c) choke them improperly (most often not enough, resulting in poor flow and atomization), and d) don't set up the linkage geometry properly. Start with these basics then fine tune the particular jet settings.

Good luck!
Thanks Cliff. I have worked with Webers for years. I understand what you're saying. That's why I was wondering about any baseline numbers. I think I have that book somewhere. I'll check if it has any info.