yes, but thats why its a landie, whats your reason for doing a range rover chassis then tvr 4.0, fitting it in might be a problem and if you say move the grill, you might aswell get a defender with a 300tdi. and then you wont have a series 3 with only a series 3 body on it. Because if you do stick the tvr lump in you will have to change the gearbox cus you will mash it up, so your gonna go with a defender box, with a tvr engine and a range rover coil sprung chassis. so tell me what is still series i.e. the ORIGINAL IDEA of simple leaf sprung, bomb proof petrol or deisel 2.25, or 200td/tdi mounted on to the original gearbox. with front grill still in place because if you it move you have most of the way to defender. with a different chassis, and engine and box and axles and steering well tell me what makes it still a 1974 series 3 lwb.
