That is a horrible idea, stick to what works. With a 1" thread you wont have much wall thickness left on your tube (if it is 3mm) also the ball joint will be huge.
Nismoid you think too much... weight, faster, money! You are jealous because it will be cooler than yours
Just do it. Buy an R32 GTR (complete) take out the running gear and sell the shell to me for real cheap. Then a**hole everything into an empty HR31 shell.
Easy right?
I am assuming you mean the upright, you have to remove the upright. I ended up using a hammer and chisel to get them out. Easy job to push new urethane ones in and inner steel sleeve. No press needed, just a vice.
Have a look at what they are actually worth mate, I bought an R32 block and cradle for $300... the shitty cast pistons are worth peanuts too BTW. Do you mean a whole bottom end (i.e. block, cradle, rods, pistons, crank) for $900?
Can't go wrong with Bilsteins and all new Superpro urethane bushes, it will cost you a lot more to get someone to do it all for you. I did absolutely every bush and most ball joints and it is not something I would like to do again soon!