<VV> LM - EM temp donor questions

[rchivers at tampabay.rr.com]

Hello all,  
     Have a problem with the 65 Monza convertable (95hp pg).  Son-in-law was driving it the other day and experienced a loss of power and a significant knocking sound from the engine.  We had replaced a head that had a dropped valve seat about a month ago.  Not sure if we dropped another one or not but the noise seems to be coming from the center of the engine.  This engine has about 35K miles on a top end, but the bottom end has never been worked since I have had it.  I am fearfull of some kind of rod issue.

I have a spare trans (pg) and diff in storage (66) and a 62 with a 80 hp sitting in the driveway.  First question, can I mate the 80 hp to the 66 tranny and diff ?  My plan is, if this will work, to remove the power train from the 65 and temporarily replace it with the 80hp + 66 tranny & diff set up.  The pg in the convertable has had a pretty nasty fluid leak that we have been unable to find while in the car.  Thought if the temporary transplant would work that we could rework both the engine and tranny at the same time.  If this combination will work are there any special concerns to be aware of ?

Secondly as we rebuild the 95hp what should we look for in the bottom end ? I have done several top ends (rings, barrels and heads) but never been in a bottom end before ?

You guys have been a great help in the past, I look forward to any advice you have to share.

TIA
Rex
65 Monza Vert (wounded) ....
61 Rampie (on the road)
62 Sedan 700 (in restoration process) ....Temporary donor ?