Twin Cam Block Cleaning

[Sherman Kaplan]

I'm getting ready to send my block to the machine shop and have a question regarding the number plates which appear to be screwed onto the block.  If the shop hot tanks the block will these plates be destroyed?   I know that hot tanking will destroy aluminum such as the jack shaft bearings.  What are these plates made from?  Can or should they be removed?

Also, does anyone have a recommendation for a machine shop in Northern Colorado?   Denver would be fine, but Loveland or Fort Collins would be great.   I do have the name of a shop, but if anyone has one they have used I would appreciate any referrals.   FYI I have sent the head to John McCoy at Omnitech, but would like  to have the block machined locally.

Thanks,
Sherman
Windsor, CO

[4129R]

The block number should be embossed into the metal.

S with 5 numbers after it.

Has your block got a big L cast into it?

[Sherman Kaplan]

The block does have the L on it.  It is the original block for the car. It looks like the numbers in the picture I posted are stamped on a plate that is screwed into the block and not cast.  Although I could definitely be wrong about this.  The L is definitely cast.

Thanks,
Sherman

[surfguitar58]

The block does have the L on it.  It is the original block for the car. It looks like the numbers in the picture I posted are stamped on a plate that is screwed into the block and not cast.  Although I could definitely be wrong about this.  The L is definitely cast.

Thanks,
Sherman

Sherman, I could be wrong, but I think the embossed plate is screwed to the pattern used to cast the block. The numbers are part of the iron casting, as are the screw heads, faithfully reproduced by their impression in the casting sand.
Tom

[jbcollier]

Are you talking about frost plugs?

[Certified Lotus]

I’ve got five twin Cam engines and have never seen the screw heads on either side of the block number as it is cast. I thought you were talking about the freeze plugs at first (yes they should all be removed and replaced).

[Sherman Kaplan]

Not the freeze plugs.  Below the freeze plug is a plate with a number starting with 701M.  I know this is the block casting number, I just  didn't realize it was actually part of the casting.  I was not sure if it was a plate that was screwed into the block.   However, I guess from the consensus it is cast into block. 

Thanks to everyone,
Sherman

[jbcollier]

I don't know of any plates on Ford engines but they were used on BLM engines and, yes, it's a good idea to remove them before hot tanking.