There was a post earlier this year about the 1254083 block, but the answers really didin't cover my question or maybe the thread go a little sidetracked. Anyway, I have this block in a 71 Jeepster Commando. The engine is an Odd Fire (yes, it is an Odd Fire) and I would like to keep the Odd Fire firing order... just because. I would like to put some 79+ heads & appropriate intake on my block, but I don't know if my block will work with the "newer" heads. My concern is that the water ports in the block and 79+ heads won't align correctly. The Team Buick website (and others) indicate that the 1254083 block was used from 75 - 87 in all types of configuration (2BC, 4BC, SFI and Turbo). So my assumption (and I know how to spell assumption) is that the "newer" high port heads will work with this block. Will they, for sure? I have an opportunity to pick up an 86 NA 231 block (Olds, I believe) at a fair price to do a swap of the crank, rods, and camshaft (maybe 350 flat top pistons) from the Odd Fire to the 86 block. FWIW, I would probably go with a 212/212 (260H) or 218/218 (268H) camshaft. If I need to use the 86 block, that's okay. I just don't want some unnecessary cast iron in my shed that I would probably never use, so just keeping my 1254083 block is my 1st choice. BTW, I have a TH400 currently as my transmission. I'm not planning for a 300 HP engine or rock crawling, I would just like some more safe cruising RPMs and better throttle response. Of course I am planning on doing the proper build on either of the engines: oiling, porting & polishing, larger valves, single plane intake, etc. I don't have enough room by my firewall for all of the plumbing that a draw thru turbo would need, and I don't think I want to go in that direction. I also was looking at a 4.1L donor but they are as scarce as ... That's the short story. Your comments and suggestions are appreciated.