Build a new cross member and do it right.. We've had people do that dumb
and hack into the pumpkin and weld a plate on so they didnt have to build a new cross member and do it right. No its not 29" for fullwidth. Its 31.5 IIRC. So build a hanger around that or.. buy one of these if you're lazy like me
http://www.sky-manufacturing.com/new/detaproduct.php?id=184 and dont worry about it.