Mr Hoyt is correct. However the 261 can be built to 278/292 CID where the 235 can not.
As a beginner stick with the cylinder head R&R for now.
By the time you 'chase down' all the parts, pay for them and get it ready; You'll have done more than most "in your shoes".
This is the "cheapest & fastst" to get the most for the least.
While you are doing all of this, you can drive your car as well.
"Hit it Tiger"
