SBC 400 block build date
 

Got a SBC 400 "509" and been trying to ID it. As far as I can tell its possibly made in Saginaw due to a casting clock on it. My friend said its an early 70's cheater block probably from a truck, and probably high nickel content. I found the following mark "H/17" which I think is the manufacture date. If it is, then the block would be from 1 Aug 1977. 2 bolt.
Two questions: how does one figure out if it is a high nickel content block and can anyone verify or ID the "H/17" mark?

tks in advance

if i recall right.......the truck block(high nickle block) had a raised half moon shaped stamp right on the back of the block on the opposite side from the block number is located :wink:

i got one in the back off my garage ... and the block is still stock and unmolested... i was gonna use it for a street build :)

I don't know that there was ever a high nickel 400 block ever made and i've ran several of them, including the one in my car and one on the engine stand in my shop. 350's yes, 400's i doubt.

JMO

Zip.

the 509 was not the nickle block it was the 817 block from the same year... but like all 400's gotta be careful cause of core shift and make sure you got steam holes in the heads and gaskets :)

3951509
3030817++
1974 - 1976 400ci 2 Bolt Mains
++High Nickel Block

Thanks fast75vega, for passing along those #'s. A person never gets too old too learn something new and i just did :oops:

Zip.

I found another source identifying alloy % content mark: "010 and 020." The first being tin and the second nickel. I got the 010 mark but not the 020 so that follows with what you found - oh well. I'm about to take it in and get it magged and all that...will help me decide how to build on it. First engine build, going to be either 406 or 427.

tks for info guys!
James

Sonic test it before you do anything!!!

cant stress this one enough...lol

no problem... that why we are all here :)