Some states now demand "originality" for the concessional rego.You must have the correct motor.Others say "period correct" is ok.A lot of this is aimed at Harley choppers and bikies.Also at hotrod builders who use vintage vehicle loopholes to put 450 big blocks in 1935 Bedford utes,using nothing original but the pressed metal.The point of this,is that for sivs rego,you are better off in a local vintage car club,because the club inspector doesnt know a great deal about trucks.The club inspector carries a responsibility under the law for members vehicle that he inspects.So a lot go much further than seeing that you arent swapping plates between vehicles at rallies.With sivs plates you escape govt yearly inspections,but the club is supposed to police a similar yearly inspection,without the rollers ,of course.You can still be inspected on the road,with defect notices and fines,which are high for trucks.