I should be able to keep the stock cab mounts. I will be makeing a full framed floor with square stock and roll tubing cover in sheet steel. With that and the addition of a full roll cage i imagine it will all be extremely rigid and safe.
Bolted crossmember, boxed the crossmember ends that had to be cut, and picked up a cd009 trans for the rb. Next on the list is finding the motor and trans location and starting the 240sx irs setup.
Crossmember mounts are made out of 3x3 angle iron 1/4 inch thick with gusseted ends. This is the second set I made the first set was 2x3 and 1/8 inch thick. They probably would have been strong enough but anything worth doing is worth overdoing so I decided to go with 1/4. They are fully welded edges to the frame and with three large spot welds just to ensure that they don't move and or break. 240SX crossmember and right-hand-drive s13 rack and pinion everything is trimmed to fit and level. Only thing left to do now is drill for holes into the mounts and Bolt the crossing over in. Next thing on the to-do list is the 240SX rear end mounts for the irs subframe and strut Towers.
I ended up buying a 240sx roller. I stripped the steering and suspension and i am going to swap it all to the 521. Here are some pics of the front crossmember fitted and some mounts please forgive my shatty welds. I have a cheap welder and little experience with it.
No i would rather not cut the fire wall. Just seemed like the easiest option. Not sure if a bed mounted radiator will cool enough and i want to try and keep a oem style. I would like the truck to look fairly stock on the exterior. Minus necessary mods like flairs for bigger tires and things along those lines. Thanks for the suggestion tho i had thought of a bed radiator or even doing a under the front radiator with a air shrouds to direct air up and through the radiator. I really will not know whats possible until i get the motor and trans test fit.