i just finished a swap similar to that but just a tad bit different. i took the leaf packs apart from a chevy 2wd and my rear yota leafs(well what was left of them lol..) and if you have access to something that cna drill spring steel just center mark and re-drill the canter hole to match the chevy leafs to the toyota leafs. it gave me about 2-3 inches of lift and stiffened up the rear just a tad but so far has offerd remarkably good flex, now mine is purly wheeler at the moment so i dont have shocks on her right now as i dont plan on a dune trip very soon.

but like i said if you dont have anything that will drill spring steel, like a ball end on a milling machine(which i know os not a very common thing to have accces to) like i had than good luck. normal drill bits will not work they dull and polish the spring steel to an ever harder level, trust me i only destroyed 11 bits ya know.

but any way that saved me the hastle of trying to relocate the spring hanger, but either way is going to have its hard points.

PS if done right you can use the chevy center pin but if you can find a longer one , just 1/2" would be proficient for a longer center pin.

nick