FORGED LT1 CRANK?

[bergy]

010 block was cast in both Saginaw and Tonawanda - made off of different masters, so core and mold equipment varied slightly in non qualified areas. No high nickel. Cylinder and bearing cap iron was all high(er) chrome to refine the grain structure & get to 30,000 psi strength (UTS). Normal gray iron (we called it piston iron at the plant) was 25,000 psi strength (UTS). Of course, running changes were made to the equipment at both plants between 1969 and 1973.

[bergy]

Grinding on the crank obscures the flash line (flash line on forgings, parting line on castings), but I agree with Eric - appears to be a forging IMO.

[Hotrodpaul]

Looks like a forged tufftrided crank to me, flange shows it to be a 350 ci, so LT-1 application.

Paul

[70 copo]

Both blocks are:

4 bolt
Saganaw cast and Flint assembled.
010 castings
One marked .20 the other no markings.
Obvious significant casting differences.

http://s952.photobucket.com/user/70c...t=3&page=1

Any one know why?

[70 copo]

Another Saganaw cast Flint assembled 010 now in 1970:

http://chevynova.org/1970LT1_Engine.html

Appears to be the same type of casting as the 1969 I used in the 1969-1973 block comparison.

[bergy]

Front & rear housing cores can be marked for multiple applications. Just like some MIV housings are marked "Hi PO" even though they were also used in low horsepower applications. Not a big mystery here.

[70 copo]

What about the differences in the center of the block?

Here: http://s952.photobucket.com/user/70copo1...?sort=3&o=5