How can you tell if a 3970010 block is a 79 or a 69 ?

Thanks !
John

Depends on the cast date in the rear of block. I think that this block went from 69 all the way to 76'. Think it ended then, so maybe yours is a 69'. I have this block in my Z, but unfortunately its a 350 truck block from 1975 with a TYZ code. Your block should have a month and day cast onto the rear edge just above the tranny. Somtimes hard to see if its in the car.

You need to see what's on the engine assembly pad also. Pre 1970 '3970010' blocks have 2 letters as a suffix ( ex. V0912DZ ) vs. the 1970 and up which have three letters ( ex. T1218CKB ).

What's your pad say?

350 # 100114997 date I 18 9 casting #3970010 front pad 00925onb

Not sure though....this is what the guy is telling me.....the "onb" is throwing me...I asked him to take a pic so I could see for myself...


John

Most likely a 79 block...IMO

According to all the sources I have, 3970010 was used from 1969 to 1979 in every Chevy 350 model in one form or another, 2 and 4 bolt main. It was shown to be used in late 69 302 Z28 but those are not that many. There are more 1969 Z28's still in owners hands then Chevy made, so it can't be a 302. LOL

I have one in my garage 3970010 Date looks like B 2 Also in timing gear area are the numbers 010 509 776 635 512 I know the 010 in nickel content I have no idea what the others numbers are. The pad has numbers stamped over numbers and really can't make out what they are but there a couple Ts and a V and a bunch of numbers I was thinking it is a 79 4 bolt main truck block I bought off my friend when he was closing up his machine shop it has bored to 30 over and line honed and hot tanked and new cam bearings and freeze plugs I this point have no Idea what I am going to with it.

Date code B 2 9 I forgot the 9

69 3970010 have full width passenger side engine stamp pads, 79 3970010 blocks have pads that are about 1/2 the width of the head.

The casting code indicates February 2nd 1969 or 79, BUT since the 390010 block wasn't brought into production until April fo 69 I would say the block is a 79 block.

April of 69 that is why I thought it was a 79 being dated coded B 2 9 But my pad with is 1.75" and 1" deep

meant to write and my pad is 1.75"

I have the same casting number with the narrow pad you describe. I'm almost certain its a late version of the "010" block, built in the 70's. Mine's a j-5-5 version..tough to read the last #. Has a TYZ, code on the pad though, which should mean its from a '75 truck.

Any block with a 3 digit suffix code is 1970 and later.