Just trawling Ebay and thought this stuff might be of interest if they are local to you:

Standard bore HQ 308 bottom end, dated 4/74. QT prefix. $500 no bids. Nowra Hill NSW. Engine number hard to see but looks like original stamps:

http://www.ebay.com.au/itm/Holden-30...item4d249c9d24

VS 304 EFI bare long motor, $399 no bids in Tatura VIC. K5 dated 10/1995 but if decked could be seen as 10/75 if you wanted to put a later engine in your HJ. Will be blank on the sides and be relieved for rods for a 350ci crankshaft.

http://www.ebay.com.au/itm/Holden-5l...item23410b90f2

308 TH patttern HZ 308, long engine. $500 no bids in SE Melbourne. M7 date code (12/77) so perfect for a 1/78 - 3/78 HZ Sandman. Ad says it even came out of a 2/78 Sandman:

http://www.ebay.com.au/itm/HOLDEN-HG...item3a97b7238a

308 QT manual complete bottom end, K6 (10/76) date code. $440 no bids in Ferntree Gully VIC. Says 60 thou but also says no wear at 60. Good for an 11/76 to 2/77 HX Sandman:

http://www.ebay.com.au/itm/Holden-30...15384385&rt=nc

13L9 (11/79) dated 308 bottom end. TH pattern. Says it is a blue but apart from the engine number it is the same block as a later HZ red. 40 thou up. $380 no bids in Maryborough VIC:

http://www.ebay.com.au/itm/Holden-bl...item23410f6941

4L8 dated (11/78) 308 TH engine standard bore in bits. No engine number given but could be QT, 11QT, ZT, 11ZT or VT. $1000 buy it now or offers in Ormeau QLD:

http://www.ebay.com.au/itm/Holden-30...item41877e797d

Pollution red V8 heads. $5 1 bid in Albion Park NSW:

http://www.ebay.com.au/itm/Holden-V8...item462810604a