As long as the pin is in good contact with the piston pin bore at its working spec. Assemble the piston in bore and you will see that the rod/pin is not always centered in the piston.

Just looked at pics. The pin needs to be moved. That is a bit too far off.

The pin can be moved with a fixture and a press. If the rod eye is at proper ID spec. the pin will not in move in normal operation.

Deck height problem can be remedied with a thicker head gasket. BBC gaskets can be had fron about .020" thru around .060" from common sources or use a Fel Pro head shim at .020" and a regular gasket.

Factory BBC tall deck 366-427 used to have a common problem back in the day. The rod eye would get finished a bit too big at production and in operation the pin would slide over and wear on the cylinder wall. Some all the way to coolant. Others just massive oil use.
I did many bore/sleeve jobs on those engines.

 

9.28:1 isn't considered low compression when it comes to boosting a motor, especially going the roots route. You could do it, but at low boost levels, maybe 5 pounds, mostly a poser thing. Turbo is a little more forgiving, but there are limits. Static of 9.5:1 will give you an effective c.r. of 13.4:1 at 6 pounds of boost.

 

Just installed the two offset pistons and they slide over to where there is even less pin on one side. Also checked my deck height and piston is .018 in the hole so I can go to a 10.5cc dome piston to get 10.3:1 and still have the piston .003 in the hole.

 

Where on the pistons are you checking the deck?

 

I checked top, middle and bottom of piston in cylinders 1,2,7,8 . When I asked the guys at the shop they said the pistons should be .004 in the hole but they are .018. I figured this out After I checked it Yesterday to see how far offset the pin was..

I didnt think i could get new dome pistons without them sticking .010 out of the deck, since they have a 1.640 compression height . Guess I can with that extra .018 ??

 

When checking the deck height it is best to use a dial indicator
and a bridge. Find top dead center of the piston, then using a straight edge and a set of feeler gauges measure to the top of the piston parallel with piston pin.

 

Yes, the pistons you have now are rebuilders replacement pistond. Usually .020 short. That would put the 1.640 compression pistons close to the deck. The quench could then done with the proper gasket combo.

 

What is the highest compression u guys recommend for the zz502 cam, aluminum Bowtie heads and EFI setup on my 454? I was thinking 10.5 to 11 on pump gas ?

Opinions?

Thanks everyone.