1983 CJ7 -258 cid strt 6. I did the 4.0 head swap #7120 casting head ported & polished, Offenhauser manifold, Holley truck avenger carb 4BBL jetted down to 270 cfi, Pacesetter headers, Magniflow exaust,Be Cool aluminum radiator w/ flocooler water pump, Powermaster HO alternator- TFI Juicebox ign