Engine and Diff details

[78Sandy]

Gday all,

I am new to the whole forum thing but hoping that some of the members out there could assist me with their expertise.

I am currently restoring a 1978 HZ Sandman Panel Van. It is a 253 4 speed.

The engine has a HR prefix on the engine number, would this been an original engine for my Van?

Also, it has a 2:78 ratio Salisbury (non-LSD) is this a standard ratio for a HZ Sandman? Or did they have a 3:08 LSD?

Any help would be appreciated,

Cheers,
78Sandy.

[Frosty]

I think the first thing you need to do is put up more details from the compliance plates as that will be needed to help with what your van was original built with.

[wbute]

HR prefix is a 253 out of a LX Torana. 3:36 is standard diff I think. That's an auto diff (2:78) and a manual 253 will struggle with a diff that tall.

[HK1837]

As above a HR prefixed 4.2L engine is from an LH or LX, same engine as what was in a Holden at the same time just the prefix plus a few minor differences like rocker covers.

2.78:1 Salisbury was gone by HZ, replaced by 2.60:1. The standard diff for a 4.2L manual HZ at HZ release was a 3.55:1, replaced mid HZ by 3.36:1. If the engine is modified to HQ-HJ 4.2L power levels you will be fine with a 3.08:1 as this is what was standard for 253/4.2L manual from HT-HJ, only replaced by 3.55:1 in HX as the pollution 4.2 was so badly affected by the anti-pollution build of the engine.
A 2.78:1 behind a 253 and M20 will be a clutch fryer, unless the 4spd has been modified to a wide ratio (M22) aussie 4spd.

[78Sandy]

OK Cheers Frosty.

The compliance plate tags for driveline are as follows:

ENG: L32 TRANS: M20 RRAXLE:CV4

[78Sandy]

Thanks for all the help thus far it's very helpfully. I am trying to keep the van as original as possible so this info helps heaps.

I have since been told that the correct engine prefix for a HZ Sandy running a 253ci engine is QR or QT. Is anyone able to validate this for me.

Cheers.

[Kingsandman]

qr 253,qt 308 start of engine no, casting date for block just above water pump engine no on passenger side just below first spark plug.

[78Sandy]

I think, from what I can establish, a RRAXLE:CV4 on the compliance plate translates to a 3:36 diff ratio.

[Innuendo]

It will be GV4 not CV4 and yes 3.36:1 Ratio