Hello,
I went to look at what I thought was a 261 today sitting in a Canadian-built 1960 C10. Based on the story from the owner, the previous owner replaced the original 235 twice with GM replacement 261 blocks.
I had a heck of a time identifying it as it has what appears to be 3836848 head for the 235, but the block has captains bars above the starter. I couldn't find the other set of bars on the driver side but it was dark and the manifolds were blocking my view. Where the block casting number should have been I found a capital "M" inside a square and that's it. There is a lot of years of gunk on the block but I just could not find the number where it should be between the distributor and fuel pump. It also appeared to have the full flow oil filter.
Since this is a 1960 truck I believe it would be almost impossible for this block to be the '53 Powerglide 235.
So is this a 261? Does the "M" mean anything to anyone? Thanks.
James
