[nineteenS10]

I have a S10 with a small block of unknown origin. I can't read the front or back numbers on the engine. My question is the 3 digit number on the side of the block of any help in determining the engine I have. Thank you DON

[techinspector1]

Remove whatever's in the way (alternator maybe) and read the code on the passenger side block deck at the very front of the block. Use a mechanic's mirror and a strong light to read the casting number on the back of the block at the driver's side. Remove a valve cover and read the head casting number between the valves.

[nineteenS10]

Thanks Techinspector1 but the block has been decked it has after market heads and reading the rear number is impossible with the firewall configuration. The only number I get is 3 digits on the side of the block. Do you know if that number will be any help.THANKS DON

[oldbogie]

Originally Posted by nineteenS10

I have a S10 with a small block of unknown origin. I can't read the front or back numbers on the engine. My question is the 3 digit number on the side of the block of any help in determining the engine I have. Thank you DON

Yes, if you're meaning the numbers on the passenger side ahead of the starter. These are the last 3 digits of the block's casting number. Not all block casting numbers are unique in the last three, but this will get you close if not dead on.

Bogie