if u have a question about how much a 6.2 will take i have had 350 ho four bolt mains, 454 tbi's, and i will take a gm 6.2 over them all all day long any day. if u r really wanting a power hog of a 6.2 buy a 6.5 turbo setup, it bolts right up to the 6.2 with little or no mods. throw a 50 h.p. shot of methenal injection at it and gain alittle more plus lower E.G.T. people dog the 6.2s and 6.5s but they will take a **** of a lot of abuse be for they go bang. the r companies out there that make roller rockers, head stud kit (a must if u turbo an NA diesel), lower main stud gartals, and more do some looking on the web site "thetruckstop.com" they have a hole form just for 6.2s and 6.5s. i personal have two a 79 k20 with a 6.2 NA, th400, np203, and a 83 k30 sleeper daully with a 6.2 NA, sm465, np203, and hands down more pulling power then any b.b. or s.b. chevy, hands down. considering a diesels tork range is almost the same at ideal and at 2300 to 2500 rpm. thats the beauty of diesels.