Sigma 2L engine block id question

[Kain90]

Hey all, been a while since i been on the forum.. ( first time on the new one anyway ) I been hard at my efi conversion on my GN wagon... came across a nasty crack in my block while fitting my magna head so I got a new engine and I looked at the id tag on the block and it starts with a M for astron but it has a * symbol at the end of the tag stamp.... so the complete id is.... M431P64475*
M530C06928
is on my old block.... I'm hoping my gearbox and new magna head will fit on this new block...

attempting to fit it today within the next few hours... thanks for any help this has puzzled me haha.

[EVL076]

M53 is a 2.6 i believe? M43 would be the 2 ltr

i could be wrong, and no doubt i will be corrected if i am

has the block got the casting of 4G52/4G54 on the side, behind the starter motor?
if its got 52, its a 2ltr, and 54 is the 2.6 (some of the blocks dont have the casting, so dont stress if ya cant find it)

also, the engine in the GN would be astron2 wouldnt it? - someone correct me if wrong :p

either way, the magna head will still go on the block, regardless of if its a 2ltr or 2.6

[amgis_obrut]

first number is a 1982 rwd auto 2.0l astron

second is a rwd 2.6 but i dont know what year or trans

[panda]

Another easy way to identify whether its Astron I or II, & the head has been removed, Astron I has dished pistons, whereas Astron II has flat tops. If there are no pistons fitted, then look for the oil pressure sender on the RHS of the block, Astron I is up the front near the timing chain cover, whereas Astron II is toward the back near the flywheel. Also Astron I has a wider sump, whereas Astron II has the narrow sump. Not sure if any of info this helps. ;)

[stealth]

hey panda there is no astron 2 in a 2lt thay only ever made astron 1
in the 52 range
just my 2 cents
cheers stealth

[EVL076]

and also the 2ltr has flat tops too, so if there was no id markings on the engine at all, that could be a misleading way to tell

didnt no bout the oil pressure sender thing tho - learned something

[panda]

Yes Stealth, you are correct, there was no 2 litre Astron II. My apologies.

[Sigmaproject]

Panda was right on the oil sender switch on all Astron II's ,including Sigma , the sender is near the rear on the exhaust side of the block. Also the removable balance shaft cover is not fitted to the Astron II (Australian)