Any idea WHAT this block is?

[Rowdy Rat]

Joe,

The three part numbers that I listed may very well be three different castings... The fact is that I only know of the "052" casting (the production ZL-1) at this point, but I'm researching the other two part numbers at this time. The 3992038 block might possibly be the same casting (although I highly doubt it), I'd bet the farm that the 3965755 block is a different casting.

I think that you're confusing "wet" and "dry" cylinder liners with siamesed cylinders (like the production 400 cid small block). A dry liner is one that is still surrounded by block material - a cylinder within a cylinder so to speak. A wet liner has very little material support from the block; it is directly in contact with the coolant and must be sealed to prevent coolant from forcing its way past the press fit between the liner and the block. For simplicity, a dry liner is pressed into the cylinder, a wet liner IS the cylinder. Both the 3952318 and 3992038 blocks are listed in GM literature as having dry liners.

Both of the 4.440" bore blocks may very well be siamesed cylinder design (makes sense that they would be)... None of the sources that I referenced mentioned it though.

The 3965755 block is as you described. The block was cast from a completely different alloy with a very high silicon content and used specially coated pistons (the coating was a nickle alloy I believe). The combination of the two kept the aluminum piston from trying to weld itself to the linerless cylinder.

Regards,

Stan

[Mr70]

Rob
I also found this part# 3952318 in my Chevrolet Special Equipment Catalog dated March 9th 1972.
It says it is a Bare Aluminum block for the 427 and 454 application in 1969.
This was the block was also used in that DEALER made ZL-1/LS-6 1970 Chevelle SS that I had posted here earlier this year.
It was from Ray Ridge in Trenton Michigan,which is now Pam Rogers Chevrolet.

[William]

The Can-Am block is easy to ID - no provision for a mechanical fuel pump.

[Chevy454]

So...did Chevrolet EVER produce an aluminum tall block? Was the Can Am block a tall block? And, was the Can Am the ONLY block NOT to feature a fuel pump boss?