[Formulabruce]

You could ball hone and clean, clean and re ring as long as you keep pistons in same holes. And use NEW wrist pins too. No ridge up top of cylinders?
For a driver, its totally possible to do this on the cheap if its all in good shape

[Dauntless1971]

Down to just the camshaft and crankshaft to remove. Five of the top piston rings were broke in half but still where they belong.
I am hoping to get the parts down to a machine shop that will check the cylinders and crankshaft in the next few days.
If the cylinder bore is within tolerances was hoping to reuse the pistons though now not so sure.

[Sirrotica]

For many years Pontiac stamped the rods with codes on the flat area on the outside next to the rod bolts, not every set was stamped, but many were. I've never seen a fracture where the codes were stamped. I've seen them prick punched from rebuilders that didn't have number punches also, never seen any fracture from them either.

99% of the blown Pontiacs I've disassembled, spun a rod bearing then the rod broke after the rod bearing welded to the crank throw, or it hammered so long the rod bolts broke.

To me it's a non issue since it doesn't create a ragged edge, and that is usually where stress risers start, YMMV.

[mgarblik]

Originally Posted by Formulabruce

You could ball hone and clean, clean and re ring as long as you keep pistons in same holes. And use NEW wrist pins too. No ridge up top of cylinders?
For a driver, its totally possible to do this on the cheap if its all in good shape

I would respectfully disagree with replacing the wrist pins if doing a super budget, ball hone overhaul. Removing wrist pins from factory cast pistons and then replacing them is a losing proposition from my experience. We have the high dollar Sunnen pin press at my shop. But almost always ruin 2-3 pistons pressing the pins out. Our rule is if the pins are pressed out, your getting new pistons. Pontiac rods take 1800-2500 lbs press typically to remove. Very hard to avoid bending the pin box. Full floating pistons a completely different situation of course. Our experience on a typical V-8 is: Ball Hone, re-ring with OE pistons vs proper overbore and plateau hone with torque plates = 4-6 HP loss per cylinder. So 32-48 HP loss doing a backyard style overhaul. Budget will determine which way you need to go.

[track73]

I don't understand why a torque plate would be needed on a "ball hone rebuild". I assume the cylinders would be worn in to the correct shape after many miles with the mains and heads torqued. I understand why it's needed if the block is being rebored. Ford did a study on that back in the 70's.

[Dauntless1971]

Yes the budget determines everything. I had planned on using the lowly 326 while saving up, plus the better machine shops at least by reviews left online have a 4-6 month wait here in Oregon. But I got took on the 326 and can't see pouring more money into the 326. Now as I get more information the stock 75 400 pistons may not be worth reusing even if within specs. Marking the rods if the engine was to be done on a budget. Now I may have to start a new thread on what would be a good combination of parts for my intended use of the 400 engine in my 65 Tempest.