quick google search:
these guys are in texas, could get a 235 from them or see about sending your 261 in. or both
https://www.mabbcomotors.com/catalog...t#fndtn-panel6
What is the overall condition of your motor? I think I commented before that the bores & deck look like more than just a couple hours run time from what can be seen in post 177
261 and 302 are not unobtainable, I've seen one of each on local marketplace in the last few months, both fully dressed, dual or triple carb 'hot rod' motors price in the 6-8k CDN range, don't see them now so probably sold. Given the population of Texas is 6x BC's there must be some come up near you as well