Swap 1978 9.9 hp piston on 1987 9.9 hp powerhead

[Force 120]

I have one bad 1987 piston and I have a good used 1978 9.9 hp piston. I want to swap it to my power head. What I see the different is the connecting rod cap on old version has one oil hole vs new version has 3 oil holes. I don't want to swap the connecting rod but could I use the older version with one oil hole or I could drill two more oil holes on the older version. Or just leave it a lone.

 

[racerone]

Is the weight of the parts the same.----Wrist pin on the 78 is smaller I believe.

 

[Force 120]

Is the weight of the parts the same.----Wrist pin on the 78 is smaller I believe.

You mean the weight of the whole piston and connecting rod. If they are the same, I could use the whole assembly to my 87 powerhead. If not the same, what is the problem of it? Do I need additional oil holes?

 

[tphoyt]

Drilling more oil holes is uncharted waters for me but a weight difference would throw everything off balance and would likely cause catastrophic damage.
Best

 

[racerone]

What kind of drill bit would be used to drill these connecting rods ????

 

[Force 120]

What kind of drill bit would be used to drill these connecting rods ????

I never try but thinking about using

Carbide Drill Bits​