This is a couple of pics of what we think is the GM repair for water jacket block off plugs in heads of the ''redblocks''.

The motor is 14022660, heads are 14028901, with the larger exhaust valves.

We noticed block was painted red and heads were black......it has the coarse thread injectors.

The heads seem to be in very good condition (not cleaned yet) minor pre-cup cracking. The piston in cylinder #8 had what looks to be a run in with a broken glow plug. No damage to the head noticed. These are the larger exhaust valves, and don't seem to be all cracked between them and intake valves.

In the photos of the heads, in the top right corner of the deck is an oblong brass plug driven into the head.

Not quite sure what the reasoning GM had for this modification, please post and explain......:)

it has the coarse thread injectors.

what is coarse thread injectors? sorry i might be a stupid question

^ in 82 I believe the heads used different injectors with a coarser thread than all other fine threaded.

x-2 the injectors with the coarse threads were used starting with the heads cast in 1981 through 1982..... however the tips are interchangable......:D

The 6.2 engines from the early 80's used to leak coolant externally from the lower corner of the cylinder head.The reason for the leak was because of the extra hole you see in your cylinder head picture that was so close to the edge of the casting.Thats why GM came out with a special brass plug to close up that particular hole to stop the leak.In 1985,the hole was eliminated altogether.

The 6.2 engines from the early 80's used to leak coolant externally from the lower corner of the cylinder head.The reason for the leak was because of the extra hole you see in your cylinder head picture that was so close to the edge of the casting.Thats why GM came out with a special brass plug to close up that particular hole to stop the leak.In 1985,the hole was eliminated altogether.

That's good info,thanks...... makes it easier to date engines and heads at a glance.....:D

Hard to tell form the photo, but my valves look the same size as yours. But my heads don't have the water port that is blocked off.
I guess it would be difficult to tell the diff in just a couple of MM from a pic though.

I'll measure the valves tomorrow (write it down this time), they were bigger than the valves in the heads from 6.5L.....post it up tomorrow:D

Cool thanks!

Never had a good chance to measure valves today, we were up to our necks in s**t....

Did notice however, when we pulled the heads off, there were two different gaskets..... after quick measurement , one (1,3,5,7) was .010'' thicker than the other.....

Need to take time now to measure, ''piston tops to deck height'', to see what is going on....

Probably someone did a repair on one side only.

Could be, haven't measured yet.....