I just got an 86 hardbody 4x4 z24, after 20 yrs with a 620 l20b!! this is kinda diffrent for me,, so can you guys get me up to speed on this z24?? and it's 'electro injection'??? makes a lot of valve type noises adjusted them all but not much diffrence, no cam or other valve wear detectale, seems clean inside, am i hearing something else?? just above idle and up to about 2500rpm mostly,no missing or other barks or howls over 120k tho.:unsure: