I did have 164S cams on my 75 3.0 before. It was ok but now after the 10.4mm CB cams, the S-cams feel really tame.
The performance (of the CB cams) from 4000 rpm to 6800 rpm is explosive! And this is only with 9.5:1 pistons, reworked heads and Autronic SMC fuel injection (courtesy of Beninca Motor, Melbourne, Australia).
I bought the cams via Kevin at EB, through Adie at AH Motorsports, it was a complicated deal, but Kevin arranged it for me. (Thanks Kevin!).
I also have a 155 V6 with a Squadra Chip. It goes well, but the top end could do better with some cams. With CB cams, I noticed that there is a little less torque below 3000 rpm compared to the S-cams. So I am a little hesitant about the CB cams for the 155 since the 2.5 with 68mm stroke is not very torquey.
But maybe I didn't do proper fuel/ignition mapping on my 75, it is still using the S-cams mapping.
I also have on order a bigger air flow meter from a 164S for the 155.
The problem is the 164S cams are not cheap and are hard to find.
Maybe somebody in the UK can ask Adie at AH Motorsports about their regrind cams, only UKP240. Or UKP400 for their billet cams. S-cams have about 10mm of lift on the intakes. CB cams (their mildest ones) have 10.4mm. I would say 10.2mm should be good with a wee bit more overlap compared to the s-cams.
I tried emailling them but they did not reply. I will give them a call, but the time difference is a problem as I don't live in the UK. Can anybody in the UK give a call an post some replies?
for specs on the CB cams go to www.colombo-bariani.com
Ta for now.