Light weicht cups give a more linear steering feel.
Rotational mass reduction will gain in better power on response. I have also the light weight cross joints and the light weight joint casings. You can easily shave off more than 10g from front axles with this parts. For stock I would recommend always weight reduction.

The SSBB upgrade is only needed, if you want the new cups with 5.8 mm balls. They are more durable as the old plastics which is pretty soft. If you only want the blue caps, I have to disappoint you. They are only compatible with the new 5.8 mm plastic top cap, because inner hole has a bigger diameter compared to the black ones.

Awesome thanks! Wanted to get a better understanding out what that meant on the track.Yea on the blue caps and new cups I got the whole upgrade new caps, balls etc. So im good there.

most upgrades related to the drive train will results in lower rotational mass which in effect give you greater acceleration and greater top speed.The degree of the impact is quite small when you take just that one upgrade into account. But when you upgrade the entire drive train, you get a cumulative impact. For example, aluminum pinions, low friction belts, ceramic bearings, lightweight gear diff, aluminum spool, light weight out-drives, lightweight double cardon joint components, lightweight swing shafts. Together, you will get a significantly faster car than without. Individually, they only provide a marginal benefit.

No, they are for use with all TRF dampers

The upgraded front and rear parts are worth it in my opinion because they dont have as much give and therefore will give a more linear feel. Additionally, the upgraded rear diff is a massive quality of life upgrade because your diff is less likely to leak.

Second, drilling a hole in the damper plastic cap will allow you to create shocks with very little to no rebound effect. Rebound is when the shock rod moves on its own to a settled position based on internal pressure. A dead shock will sit where ever you pull the rod too. Shocks with rebound generally have a different feel than shocks without rebound. Often times this feels like your springs are more stiff than they actually are. My recommendation is to drill the hole and never look back.

The 5.8mm plastic tree can only be used with the new SSBB blue aluminium dampercaps, because inner diameter is bigger. They will not fit on the old SSBB black aluminium caps.

Blue damper caps >>5.8mm
Black damper caps >>5.0mm

The 5.0mm plastic tree is also for all TRF dampers.

Anyone having issues with making zero rebound on SSBB dampers? I'm using the new 5.8mm caps and I've been able to make the dampers act consistently, but not zero rebound. I always have around 1mm rebound and 1mm negative rebound. The cap has been drilled and I usually build the damper by fully compressing the damper and then rolling the seal over to remove excess oil. I'm also using a shock pump so 100% its not an air bubble problem, and the same build method has worked on my regular TRF dampers and Xray dampers.

According to your descriptions, you have 0 rebound. It's the oil seal which cause this phenomenon. But it's not really a problem.

Use the red foam if you want to have rebound

Tried it, and its slightly better but still getting negative rebound. Honestly, I might just get TRF418 damper stays and run the regular dampers. These SSBB dampers have been such a big fuss for me, and it doesn't help that TRF parts are always scarce. If I broke a bulkhead I'd probably just jump ship to another brand since I wouldn't be able to fix my car without buying a completely new one. It's damn hard to be a Tamiya fan nowdays