Engine dating

G'day, just wondering how you tell the difference between a 74 block and 84 block, apart from colour.

Cheers

Engine number, 74 model 253 would start with QR. 84 model 253 would start with WR. Same for 308's earlier ones where QT,11QT etc later ones where WT, VT etc.
Also the later 308/304's had 5 0 cast on the side of the block where earlier ones had 308.
Does this help any Mark?

Yeah thanks Rob, clears up heaps.

If your unsure mate, than post up some details of the motor. Start of engine number, not the whole number! And some pics, I'm sure Troy or someone here will be able to clarify it even more for you dude.

Will do tommorrow

yep, send up the numbers and we can work them out for you

an 84 block will still have 308 cast into it....if the block has been decked and another number stamped onto it correctly there is no way to figure out if it is early or late except by speculation..

X ray it!

The Zodiac wrote:X ray it!

yeh but who really would give a flyin fork...

Not me Greg, but you'll always get the anal rebuilders who have to have everything date matched and factory correct. If that's your thing great, I can appreciate a nice factory rebuild but don't get too excited over big nut master cylinders and date stamps, rather enjoy the car for what it is.
Than with restamping, as you said decked blocks and recovered ones get new numbers too. Injected motors had 5 0 on them.

even weirder trivia of the 6 vn/s 304s ive pulled down all have 308 stamped on the crank. 304 blocks also have 2 extra bolt holes per head

I love hearing about this stuff. There's so much knowledge on this forum - you guys are great. I wa thinking about building an interactive web page at some some stage that deciphers engine codes, trim codes and so on.

Think there would be any interest in that?

Someone once told me it's the number stamped on the top of the rocker cover that's important!

pez350 wrote:Someone once told me it's the number stamped on the top of the rocker cover that's important!

Only when your building a stroker!

The Zodiac wrote:Engine number, 74 model 253 would start with QR. 84 model 253 would start with WR. Same for 308's earlier ones where QT,11QT etc later ones where WT, VT etc.
Also the later 308/304's had 5 0 cast on the side of the block where earlier ones had 308.
Does this help any Mark?

just to confuse you more.308, QT aussie block 11QT turbo block. late HZ block is ZT,WB Statesman is 11WT and late is 12WT few WT and WB 253 is WR prefix. commodore block for red and blue and black VB to VK is a VT prefix and VR for 253. to see if its a red blue or black you would have to look at the casting date. the last digit is the year. and the 304 5L gets really confusing

i think early HQ 308 block is QT but the cast date is month day year. 74 on is day month year.

FreeMason wrote:

The Zodiac wrote:Engine number, 74 model 253 would start with QR. 84 model 253 would start with WR. Same for 308's earlier ones where QT,11QT etc later ones where WT, VT etc.
Also the later 308/304's had 5 0 cast on the side of the block where earlier ones had 308.
Does this help any Mark?

just to confuse you more.308, QT aussie block 11QT turbo block. late HZ block is ZT,WB Statesman is 11WT and late is 12WT few WT and WB 253 is WR prefix. commodore block for red and blue and black VB to VK is a VT prefix and VR for 253. to see if its a red blue or black you would have to look at the casting date. the last digit is the year. and the 304 5L gets really confusing

jamie..QT and 11QT can be both turbo and tri/aus pattern blocks and these engine number prefixes ran through hj hx and to late hz where they became ZT and 11ZT..the 11 in front of the letters meens it is from a statesman..this carries through to wb statesman but when it comes to 12WT it is from a wb caprice. ....

my bad thank you Greg.