23 or 18 spline?

3rd gear woes for hard street driving I found to typically be the syncro. (At least started.) And it's not just an A833 thing. I believe its because harder de-accel demands are typical in 3rd gear.

What I don't know. Is if an 18 spline syncros are any tougher than 23?

With Centerforce clutch the pressure plate is bigger for an 18 spline to accommodate the larger diameter disc. So it's not a direct tranny swap.

Just my 2cents.