82 to 86 differences

[93hummer]

Guys,

I have an 86 6.2 truck with a locked up bottom end and just acquried a red 82 replacement. The 86 engine has a lot of good newer parts, injection pump, rebuilt heads, etc. Can I use these on the 82? I know the 82 has a few differences, but is there any reason I can't mix and match injection system and head related parts? How about head gaskets? Do the passages line up?

[Edahall]

Guys,

I have an 86 6.2 truck with a locked up bottom end and just acquried a red 82 replacement. The 86 engine has a lot of good newer parts, injection pump, rebuilt heads, etc. Can I use these on the 82? I know the 82 has a few differences, but is there any reason I can't mix and match injection system and head related parts? How about head gaskets? Do the passages line up?


You can use the injection pump and rebulit heads on the 82. However, the 86 heads won't deliver the fuel economy of the 82 heads. I get nearly 30 mpg with 82 heads that have cracks in every valve seat. The injectors from the 82 and 86 have different threads.

[Robyn]

As mentioned. X2

Yup Yup, just the injectors wont fit. The 82 has coarse threaded injectors.

The heads will fit as will all other accessories and goodies. Just use a fine threaded injector set for the 86 heads.

The internals are all the same too.


You can (If the heads have not been cut with the precups in place) tap the cups from the 82 heads and install them in the 86 heads.

Make sure the cups are when installed, from flush with the head surface to about .002" above the surface.

Never below the surface.

Just clean the pocket out good with an end brush on a drill motor or die grinder and make sure the cup is clean too.

Take care to get all the little corners in the heads cup bore all clean and free of carbon before tapping the cups into the newer heads.

Make sure the cups you use dont have any cracks in the precup fire slots that are over 3/16 long and or cross the gasket fire ring area.

The 6.2 N/A cups generally dont crack much.

Have fun

Missy

[93hummer]

Just checked the codes, this has got to be one of the earliest motors, 14022660 block with a date code of 3-2-81.

[Robyn]

Yup

Old Red block.