I have the later UNC threads, so all good there.
The pistons I have with this kit are the low comp ones. I’ve read different claims of 7.4 and 7.9 to 1 CR for these. I do not like these pistons, they’re a botch job IMHO...
With the T140E there is a nice angled squish band machined into the combustion chamber and the stock 8.6:1 pistons have a matching angle. The low comp pistons do not, they totally waste the potential squish.
However, even with 8.6:1 pistons, in my experience, the squish gap is usually way too much (probably due to tolerances in Meriden at the time).
My plan is to use some new, standard sized 8.6:1 pistons with the rings off of the low comp pistons (for the Nikasil bore) and set up the squish somewhere between .030”-.040”. This will give a good functional squish and somewhere around 9:1 CR I reckon.
To achieve this, I expect to have to skim the barrel.
Well you did ask...