I believe the stock Kia axles will fit the Capri. A quick glance at a parts listing on RockAuto shows the outers are 26 spline, which is the same as the Capri.
I believe BF swappers who cannot get ahold of an XR2 intermediate shaft opt for the single-piece Kia axle
You lose the equal length axles, but gain availability and simplicity.
If you pop a M-Factory in there order one for the Capri axles, and use the capri axles - it becomes a non-issue
Kia Sephia’s axles will not fit the Capri. The Sephia is based on the BG chassis (axles are too long) and the G series MTX tranny found in the BP equipped Sephia all have 28 spline differentials. The knuckle’s hubs were 26 spline, until mid 2000 where they changed over to 28 splined hubs too.
The XR2 intermediate shaft delete (where you use a Kia axle) is from the Kia Rio, which is based on the BF chassis. Unfortunately, the Rio MTX tranny is a F series, but it does have a 26 spline differential and 24 spline hubs like the XR2.
Throw in a probe diff or a capri one? can I throw in an N/A capri diff?
The Capri’s F series N/A differential will not work, the cheapest and easiest way to convert the Kia’s BP tranny to 26 spline is to get a 97+ Escort tranny and swap the shafts and differential into the Kia’s case.
The 97-00 escort sedan has a final ratio of 3.85 with wider 3-5 gears and the 98+ Escort Zx2 has a final of 4.1 with shorter 3-5 gears.
You can find tons of Escort trannys for about 100 bucks in the junkyards, but if your goal is 300hp, I would invest in a Mfactory LSD.