I've already done the needed information gathering for this and the inspectino of all engines in the J family for compatibility.
you're looking at around 8-10k swap easy. and that's not turn key. the engines cost close to 2k themselves. everything will be custom, down to the engine management.
The engine will fit, but it will be need to be mounted about 3.8cm lower in the chassis and since it will require an adapter plate to the transmission it would be a smart idea to get some rear transmission mounts made to make sure the engine sits in the correct place (fore and aft) in the chassis.
like i said 8-10k easily and that's not turnkey. probably close to 15 if you get it done right ready to drive out the garage.
Like LegendC said, the C35 block is smarter. it's nowhere near as much custom work...get some front mounts fabbed up (weld the chassis mount potion of the Legend to engine mount portion of the RL)...swap the camshafts and rocker assembly (i believe it's a bolt in affair) from a Type I or Type II in the head of a C35 to get the firing order to line up with the engine management of the Legend and you would be good to go.