Big Block Number Problems Down Under

[Greg E.]

Hi every one

I have a 1971, LS5, 4-Sp Vette, i'm after some help with the numbers on my block. After seraching high & low for the date code on the block in front of the starter motor, i can find no evidence of a code at all ??. The Vin, Engine, & chassis numbers all match & the broach marks are clearly evident on the engine pad.

The number cast into the block behind the right hand cylinder head in front of the bell housing is incorrect for a 1971 454, the number casting i can see is A28 (i think an X) 71??

I you need any more information, please contact me!!!!

I hope you can help me with this problem down under!!!!

Kind regards...

Greg...
Australia.

[Jack H.]

Re: Big Block Number Problems Down Under

The casting date for BB cylinder cases started out being directly behind the RH exhaust manifold on the lower side of the block... Those with early BB's find this a 'joy' area to get at and read!

But, by the time your car was built, the block casting date moved to the rear 'apron' area to mirror the convention of SB cylinder cases. The apron (also called a 'flange') is that area behind and below the cylinder heads where the bellhousing bolts on.

There's a RH and LH side to the 'apron' or 'flange' and they meet in the rear center of the engine. Look for both the block casting number and casting date to be there. You may have to spray some carb cleaner to rid the apron surface of dirt/oil, but the numbers you're looking for ought to be there...

[Greg E.]

Re: Big Block Number Problems Down Under

Thanks again for help Jack!!!!

In regard to A 28 71 date code on the right hand side of the block on the flange where the bell housing bolts on, is that the 28th January 1971??

All the best Jack & again thank you!!!!

Greg...

[Terry M.]

Re: Big Block Number Problems Down Under

Thanks again for help Jack!!!!

In regard to A 28 71 date code on the right hand side of the block on the flange where the bell housing bolts on, is that the 28th January 1971??

Greg...

Yes it is January 28, 1971