i have a 21r motor it has 84mm pistons dual timing chain 35mm round ex ports 37mmx42mm in ports combustion chamber is round with 26mm dome deapth it came out of a 1983 4x4 truck i just bout i that it was a 22r any one know about the 21r motors ?i think my head is a 22r im tring to rebuild it cant find parts. i can bor it out to be a 20r but i dont know if they use the same engine parts

 

Don't waste your time on that block, get a 22r core and rebuild that.