6.2 Pre-cups

[Chevypoor]

I am working on a 6.2/ 6.5 hybrid. One of the 6.5 heads has two minor cracks in the bridge between the valves. Both of the 6.2 heads are in great shape so I am going to use them. Since they are off of a 93 the injectors and everything else look identical to the 6.5 heads.

The 6.5 heads have some pretty decent cracks in the pre cups. I was thinking about using the 6.2 pre cups since they are better shape. The motor was a vin J and visually the hole in the pre cup looks taller than the 6.5 but not as wide. The 6.2 pre cups have 3 squares on them and a circle in the top corner with an A in it. All I can see on the 95 cups is a small circle. Will the 6.2 cups cause me any issues fueling/ smoking wise. The truck the motor is going into is the 95 GMC K2500 listed below in my sig. Thanks!

 

[tanman_2006]

You will probably have to back the fuel off if you use those.

Get ahold of slim and see if you can send yours to his precup honing guy to get the 6.2's opened up.

 

[WarWagon]

You will probably have to back the fuel off if you use those.

Get ahold of slim and see if you can send yours to his precup honing guy to get the 6.2's opened up.

:nonod: Don't run the 6.2 precups with anything but a stock turbo. They smoke more than the turbo precups even with a stock turbo and are really bad with a big turbo. I would absolutely get them machined out or find another set by any means necessary. I have 6.2 precups on my 1995 with the ATT - it is a coal train even on the factory tune also with the HX40II. 6.2 precups in the 1995 is the #1 regret I have, but, no one knew anything about precups when I dropped the engine in and the 6.2 cups run well enough on a small stock turbo not to notice. It is sluggish off the line.

Buddy tried different fuel and timing to try and clean it up with no success.

 

[Chevypoor]

OK thanks guys. That was what I was afraid of. Since the 6.2 cups are not 100% either I think I would rather run the newer diamond cups. Anybody know where I can get a set of diamond cups?