lol, perhaps they thought what the hell it's one HQ Holden taxi, it won't last the distance anyway so why not let the bloke have a go.
Actually what they should have done is raced it as a 308, and argued to be allowed to use the already homologated L34 engine (like was allowed for A9X). Then they'd have had a slightly heavier car with the same engine, box and brakes as the L34's but with a far stronger rear axle. HQ's can and do handle well if setup right (just like an LH can be made to handle as they were both hamstrung with similar setups). When you look at the qualifying times for the car as a 308 and then a 350 it qualified 20th and 17th respectively for 1973 and 1974 which isn't that bad - lots of privateer GT's, XU1's, L34's etc qualified behind it. Interesting that in the Muscle Car Masters today if you run a 308 in a HQ your minimum weight is identical to an LH.