casting# block 2202857-7 & intake 4104595 yr??

Ah! OK, that I can work with. 2463 395 is the part number for the 170 block with standard-compression pistons and rings in '64, '65, '66, '67, 68, '69, and '70-'71 (170 for export only).

For the 225, on the other hand, we see 2463 399 as the block-and-standard-compression-pistons P/N from '64 through '67, then in '68 it becomes 2951 694, where it stays through at least 1974 (and is also the 198 block-and-standard-pistons P/N starting in '70, because the only difference between a 198 and a 225 is the crank and rods). That jibes with the '68 introduction of the new RG block with five freeze plugs.

So it looks like the answer is almost clear: LG (170) engine blocks stayed with the older design, with 3 freeze plugs, right on through to the end in 1971.

But not 100% clear, because the '69 US FPC (and only the '69 US FPC, though I no longer have a '69 Canadian FPC to check) also lists 2453 772 as the 170 block with standard-compression pistons and rings with the notation "CANADA". There are also "CANADA" part numbers in the US '69 FPC for standard- and low-compression 170 and 225 blocks-with-pistons and short block assemblies. These P/Ns don't show up in any of the other US FPCs (eventually I'll be able to check '64, '65, '67, '68, '69, and '72 Canadian FPCs next time I'm at the shop I sold them to).

It's not unusual to see "peek-a-boo" stuff like this when trawling through FPCs. Sometimes stuff like this is the only readily-available clue that there were plant-to-plant variants, but sometimes it's just an artifact of the enormous job of cataloguing and organizing such a vast mountain of part numbers and information. A little less info than was intended gets supplied over here, a little more over there. I've lost count over the years of how often I've finally chased down an otherwise-invisible part number for a [year, model, part] by looking in a different-year FPC.

But even lacking a look at those other-year CFPCs for now, these "CANADA" numbers are interesting because the '66 Canadian FPC lists the same part numbers as the '65, '66, and '67 US FPC. The '66 CFPC also lists 2453 789 for the 170 block with low-compression pistons (an export setup); that same P/N is given in the '69 US FPC for 170 block with low-compression pistons, noted "CANADA". The '66 US FPC (and all other-year US FPCs from '64-'71) gives 2463 396 for 170 block with low-compression pistons. We havin' fun yet?

The US/Canada Auto Pact was not in effect for the '66 model year, but it was in full effect and Chrysler took full advantage of it in the '67-'68 timeframe, before the '69 model year, so it's a little odd that there would be Canada-specific engine block part numbers like this in '69. It suggests that Windsor Engine Plant was doing something a little different than Trenton Engine Plant, and had been for awhile given the relatively old (2453… and 2651…) part numbers on the "CANADA" blocks listed in the '69 US FPC.

I don't know how many freeze plugs one would find on any of those '69 "CANADA" blocks. But given the age of those 2453… part numbers for 170s coming out of WEP, the odds are very high there were no 5-plug LG blocks.

And now Uncle Dan needs a whiskey.