I have a 509 -400 block with the #'s 010-020 with the # 509 between the 010-020 ,also the#'s 512&532 on the other side of the area plus the number G18.I know about the 509 010 020 400 blocks with the high nickle and tin content.I also just got my hands on a 350 standard bore block,here is my question,the 350 block that I just got has the 010-020 with the 509 in between the 010-020 under the timing chain area,plus the #'s 512 & 532 on the same side as the 400 block plus the # G16,I thought that only the 400 blocks had the 509 #'s on them.There is the #'s on the pad on block,as follows c4u162575 VO320TML .Could someone run these #'s and give me some Idea what kind of 350 that I have and if it is worth building a 383 from,any help would be appreciated,,,,Thanks Camaro BOB
68 RS 302
Mar 23rd, 06, 07:53 PM
The "TML" suffix is this from the nasty Z-28 website:
1974 TML 350 van & bus 145(HP) 2(bolt) C-10 & 1500
1980 TML 350 van, bus, m/t, Cal M LT9 170(HP) 4(bolt) C-30 & 3500
Mar 24th, 06, 05:40 AM
What are the full casting numbers of the blocks? That will tell the story.
Mar 24th, 06, 11:52 AM
The casting #'s on the back of the block are 3970010
Mar 24th, 06, 12:02 PM
I have another 350 4-bolt main short block that has the casting #'s 3970010 but it does not have the 010-509-020 under the timing chain,or any of the other #'s as well.so what am I looking at. Thanks for the input Camaro BOB
Mar 24th, 06, 12:05 PM
I forgot to tell you that the dip stick is on the drivers side of the block
Mar 24th, 06, 02:46 PM
A 509 casting 400 block has the numbers "509" cast into the sides of the block in big letters -- like 1" tall.
The 350 block will not and the 509 under the TC cover doesn't mean its a 400 block or a "509" casting.
Mar 24th, 06, 06:54 PM
the suffix code you give TML is for a 1974 Chevrolet Van 350 engine. cast 3970010. It had 145hp and a 2 barrell carb. RPO: LF-5
Mar 25th, 06, 12:09 PM
The casting #'s on the 400 block are 3951509,it has the steem holes between the siamazed cylenders and it does "NOT" have 509 cast on the side of the block.I ran the #'s on this site and they told me thet it was a true 509 400 and that it came out of a 74 chevy taxi cab.The 350 has the 4 bolt mains and the 509 #'s and the 010 020 ,and if this is a 74 van 2 bl engine why would it have the 4 bolt mains and the #'s like the ones on it ,,,Is this a good block to build a 383 with or not.THANKS Camaro BOB
Mar 25th, 06, 12:41 PM
That's interesting, I thought all the 509 castings had "509" cast into the sides of them like mine. Mine is a 71 casting out of a truck.
I think your 350 block would be good to build a 383 with, but you never know for sure until you get it to the machine shop. If its standard bore and will clean up good at +.030 you are in good shape.
Personally I prefer pre-75 blocks because they were still made in USA -- I think it was 75 or 76 they started making them "Hecho en Mexico"
Mar 26th, 06, 02:50 AM
This block does not have the "hecho en mexico" anywhere on the block.