i am in the process of rebuilding a 1978 or 79 20r and the new piston rings that i had ordered(seperate from crank kit) were to small. they were for a 88.7mm ? piston and mine has a 93mm piston in it like in the 22r . the engine i was told came out of a 2wd pickup. i had bought the engine for $50 and run it in my trail buggy for 2 years. the oil pressure went south and spun a bearing, the engine had more pony's(seemed like to me) then the other 2 22r's i had had in it. questions is would anyone know what this engine would have come out of having the bigger 22r pistons in it. my thought might be a rv or a box truck??? any thought's.

(by the way it is stamped 20r on the block and on the head under the cam and i dont think it has been bored out)

 

i scored a 78 for free, the guy was going to pay someone to tow it away, he ordered a crate motor for it had it bored .40 over, has an RV cam, headman headers, i scored a weber 32/36 for $20, and the adapter plate for another 20, runs like a beast and has loads of torque.

oh and I forgot to mention that yea, it probably was being build for an Rv, that's what the guy said he was building mine for until he couldnt work on it anymore