The Rover engine, being aluminium, is a lot lighter than any of the Toyota 6-pot engines and may possibly give you an unsprung weight problem/s with your truck. Like Grimbo says - it's an old engine - which was first debuted by Buick in 1951 and is probably why most folks going V8 choose the 350 Chevy motor which these days is a lot easier to find and numerous companies do the conversion plate/bell housing to suit. Unless, of course, you have a Rover V8 in the back of the garage. Various LRs, in the past, used that engine so maybe one of their adaptor plates or bellhousings would be a suitable starting point. Regards, Rodger