Yeah im not talking about ca auto,im talking jatco or something along the lines off c4.

An auto can still break, but they are cheaper to buy

I had an auto 1200 trans tunnel welded in and it was still not big enough for the CA18 auto box. There was still some manual massage-ing that i had to do

Do you want to drive auto or manual? That's wat it comes down to

Hi guys I also have a ca18 5 speed and as mentioned before will be starting out with 300hp minium then will be going up from there.So im wondering whether or not I should just go auto and not have to worry about it in the long run.

400hp dosnt mean Much to a gear box but it depends how hard its flogged and thrown threw the gears.thats what break them most the time

Ok so moddinh the tunnel is a must. Then just ca gearbox is good enough for about 300-400hp?

You need to mod the tunnel unless its an auto tunnel then might just need a little massage. If you got access to a hoist you can get underneath and use a short hand sledge hammer with some flat wood and stretch it from underneath. I did this to an early K series corolla to fit a bigger W series box.

No box will fit thats small enough for a CA otherwise

So what do you guys with ca conversions think is a strong box
Without modding tunnel?

I also have a short shift kit for my 71c box

The D21 71C box Supafatto is offering is a bargain considering its condition

I will also add the 71c boxes on the d21 have improved dual synchros and larger bearings on the imput shaft as some Z guys use 71C internals these days but have some machining to allow for the bigger bearings. The R30 71B stumpy been much older they do suffer from overheated stressed shafts which are often passed in rebuilds but wont last long behind good hp.

Also the 71C also has a quick shift available for 50-80 dollars and a nicer improved setup similar to the Toyota W series.