Picked up another 87 Suburban, This one has a TBI 454. Bought it for parts. Got it really cheap.

The engine runs suprisingly well. Drove it home, but...it's got what I and the previous owner believe is a case of piston slap in one cylinder (reason for the great deal). He unplugs a certain spark plug and the knock under load disappears. Going to check a few more things before I tear into it. He dropped the pan and doesn't believe it's a rod or a main. It hasn't gotten worse after driving it a fair amount.

If it is piston slap due to a collapsed skirt and the bore is not excessively scuffed, how feasible is it to drop the pan, pull a head, maybe hone it with drill to break up the glaze, clean out the debris, replace the bad piston and rings, and run it for a while without incurring the expense of a rebuild?

Where can I find an identical factory 454 piston (new or used)? Where can I get the part number? What type of rings would you recommend?

Anybody done this? How did it work out? General opinions?

 

I did a GenV 454 engine like that at work years ago. It was a low rpm truck engine. It had a seized wrist pin. Simply changed the piston and the customer was happy. Not a proper repair job but it worked. Picked up a piston and rings from the local GM dealer.

 

Called my local dealer about a piston, wanted $210 for one.

 

Found a used piston and rod from a Gen 5 for $40. My 454 is a Mark 4. Piston looks the same but different part numbers. Silvolite says they are both 5cc, but not sure if the weights are the same.

Anybody else done this or have opinions? Ring recommendations? Other tips?

 

Get a scale and weight them. If they're within a few percent of each other you're good to go.