They didn’t drop the L36 with VK, they remained until the end of 1984 in WB. I agree though that a red 253 won’t keep up with a blue one. Unless you get the higher comp 9.4:1 red 4.2 (pollution), throw the intake in the bin where it belongs and fit a decent intake to it like a Performer or the KC multifit XT5 copy, and a Quadrajet tuned to suit the engine. Then they are pretty much the same thing with the red engine having a small amount of extra compression.
The HQ SS did show what a 253 was capable of though, by nature of it getting a 3.36 rear axle and dual exhaust. It was almost as quick accelerating as a stock HQ 308 manual sedan or coupe which also had a 3.36 rear axle but was hobbled with a single exhaust.
Here are some road tests top speeds:
HT 253 manual (3.08 rear axle):
Modern Motor, August 1969: 111.2mph (185km/h)
Wheels, August 1969: 111.2mph
Sports Car Road Tests No6: 112mph.
HQ 253 LS, Modern Motor April 1972 (I think auto 2.78): 112mph.
HQ SS, Modern Motor January 1973 (3.36): 110.5mph.
HQ 253 manual. Wheels June 1973 114mph.
Apart from any aero differences HJ is the same car as HQ when fitted with the 4.2 engine.
I don't have the HX and HZ figures at hand but given that apart from the first handful of HX 4.2 fitted with 3.08 rear axle standard, the standard rear axle was changed to 3.55 everywhere except Premier which was auto standard. It remained this way until mid HZ when it was changed to 3.36. Neither 3.55 or 3.36 behind a manual 4.2 is going to have a higher top speed.
I do have HQ 308 manual GTS (3.36 rear axle, single exhaust) in Modern Motor February 1973 at 119mph which shows you the extra power/torque of the strangled (with single exhaust) 308 will push the HQ through the air harder than a 253 ever could, when the HQ SS with dual exhaust and 3.36 rear axle only managed 110.5mph.
Found HX Sandman ute and van in Motor Manual October 1976. Both with 3.08 rear axle and single exhaust. Ute was M41 and van M21. Doesn't actually give a top speed for the van, just says NA but it did 140km/h in 3rd. The ute says "off the clock" in 3rd which is hard to believe as these had a 220km/h dash, so I think they didn't take into account a speedo error that is reported at 30km/h at 110 (110kmh actual reading 140kmh). Using that same % error at 220km/h+ means it could at least do 173km/h. Van shows spot on.
Found HZ Sandman van in Motor Manual January 1978, 5.0L manual (3.08 rear axle and single exhaust), top speed 170km/h. Not bad for a big heavy lump. 4.9 manual XC Sundowner with 2.92 rear axle gets to 160km/h, as does the Drifter with 4.3L 6cyl, manual with 2.92 rear axle.
There is a road test of a HJ GTS that escaped GMH with dual exhaust in proper tune, I haven't got it yet but it was very quick.
There is a very interesting road test in Motor Manual in May 1974 where somehow GMH let slip the very first SLR5000 in proper tune to the Press, and fitted with the optional 3.08 rear axle (and 13" tyres). It never really appeared again afterwards, and all road test cars after that were far slower and fitted with 2.78 rear axles, this sort of thing happened before where the odd car got to the Press in proper tune. It pulled a top speed of 125mph and standing 1/4 mile of 14.9s. Remember this is with a tiny dual exhaust not much larger overall than a single 2" pipe and with the lower power HQ type engine. It is that close to PhaseIII and HG GTS350 times it doesn't matter. Really shows you how quick a later LH or early LX 5.0L with the proper 250hp engine optioned with 3.08 rear axle would have been. Give it 2" tailpipes and a proper tune and it'd be a weapon.
Edited by user Monday, 27 April 2020 10:26:07 PM(UTC)
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