Super A lower sleeve seal question

Hi Guys,
I've finished my block change/rebuild on my Super A. It's running great with no leaks, inside or out!! But during the build I ran into a snag that I thought you guys could help me clear up.
When I went to install the sleeves that I took out of the original block into the new block, they were too small. So I had to use and reinstall the sleeves that were in the new block. The original block has the serial# 251069R1 (1948). The new block has the serial# 354898R1 (1954). When I was looking through the parts listing on this site I saw that there are serial number groups. Group 255418-310299 seems to be the most prevalent in the parts listing. As you can see, nether the old block or the replacement block fall into this serial# group. So how many different sleeve sizes and sleeve seal sizes are there? Is it one for pre 255418, one for 255418-310299 and one for above 310299?
And what about the width of the sleeve seal groove? I bought new sleeve seals here on this site (they only offer one size sleeve seal)and they turned out to be O-rings that were WAY to narrow and I don't think they went deep enough into the groove either. I'm really confused about this one. I was able to solve my sleeve seal dilemma but that's a story for another post.
What do you think?
Dave

The 251069 block came with 3 inch pistons with a 3 &1/8 overbore kit. The 354898 block came with 3 &1/8 and went to 3 & 1/4 overbore. They take different o-ring seals. Very common if you are working on them very often.

251069R1 and 354898R1 are part numbers for a bare block, not serial numbers.

You need to measure the OD of the sleeves where they seal at the O-ring. Get your O-rings from I-H too many places sell import stuff and thats one place you need original is those rings. You have a sued tractor and sometimes you just dont know what someone has done

The orignal block sleeves would measure 6-7/8" in length and the od of the sleeve at the seal is 3.312". The sleeves in the 354898R1 block
measure 7-1/32" in length and the the od of that sleeve at the seal is 3-7/16". Hal

Rodger that, Block numbers not serial numbers. Thanks for that corection.