I hope this will clear things up. Japan had many dealings we were not privy too until later. The 235 molds were sold to Toyota and they changed the oiling system and called it the 236.1. Its the same engine with a jap carb and modified head. The 2F motor or called the 4.2L is the 261 Chevy with a japanese head amd carburetion. They lowered the compression to 7.6:1. They usually came with 3.70 gears and got about 10 mpg like my friends sons get with a 4 speed and no OD. He bought my 250 with 9.25:1 and other mods to replace his gas thirsty 2F/4.2 or 261. They should have left it stock with the american head as it would have ran better and got better mileage. I have researched this thoroughly so I hope this info will help. I also checked at more than one machine shop. I believe the 2F was discontinued in 1986. I suppose you could deck the block and mill the head a bunch to bring up the compression or use higher compression pistons to help it out. The jap head is junk but with porting and polishing and finding some way to put on a better carb set up would make a big difference. My friends sons runs good but lacks power big time. Doesn't like hills with such low compression and poor carburetion. Just some info for those who would like to know. BTW Longbox, it would indeed be nice to find a stash of unused 235s or 261s. They are one tough engine. I know that GM made different engines that ended up in Austrailia. Such as the GM Holden car company. Mainly Chevrolet they were but special ones. Some were similar to the ones here but with better compression and other things that made them perform very well along with better mileage. They did make over there an all aluminum block and head 250 Chevy that was a screamer. A machine shop owner here has a friend that has one. There are a few left over there and they eat BB for breakfast. Would be nice to get one and ship it over here. Also the 261 was available in Pontiacs from 57-62. You could get multi carbs on them. That package was not available here but up in Canada they could get them. There has been many deals like this where we got screwed by our own manufacturers and sent stuff over seas we could not have here even before the environ "MENTAL" ist were around. Even a special super high performance slant six was sent to Austrailia and it put out 304 hp. We never saw it here or the turbo diesel version either and several other versions. The best we got was a short time offered Hyper Pack that gave 190 hp. A far cry from the other one.