Just wondering if anyone has done this, I can get stainless steel 993 valves with 8mm stems
The specs are about the same length, but they have a shorter tip (3mm vs 6mm IIRC) and the retainer would be higher, but that can be easily corrected with shims. The valves are stainless so cutting them down to SC head size is no problem.

Advantage is reducing weight on the valve train, the weight savings are greater than TI retainers so in effect I could keep the stronger and cheaper steel retainers or just use TI retainers on the intakes.
My cams don't have huge lift, but do have long duration. WEB 120/104, much like a MOD S or GE60 cam.

Just wonder if this work is worth it or not for my cams.

BTW Labour is free

Interesting idea and haven't tried it. What RPM are you shooting for and is the rest of the engine lightened also? I'd be more worried about it with GE80's with 3.2L heads (and their way-bigger ports) but haven't built anything with the 60's.

How much lighter are the 993 valves? I never weighed mine.

Hmmm, do I remember there were large-port SC heads also?

With TI retainers you are saving about 8-10 grams, I think 993 valves would easily be double that savings. I'd have to cut the heads down to SC size to know how much for sure, but the ones I weighed were about 15-16g lighter than stock SC valves.