Okay can someone clarify this for me, the LT1 and LT4 are very similar engines in fact a LT1 can be turned into a "LT4" (not exactly the same but very similar), but the LT5 is a whole different bag of beans all together and is not like either of the other two?

 

LT4= LT1 with great heads, wilder cam, and 1.6 roller rockers.

LT5= DOHC 5.7L engine having next to nothing in common with traditional small block chevy.

 

The difference between the LT1 and LT4 is pretty much the same as the differnces between the LS1 and LS6. The LT4 has a better intake, heads, cam and tuning. There are also many smaller minute differnces like slightly different clearnaces, light valves, raised intake runners, lack of egr and a few others. The LT5 is a dual overhead cam motor that was designed by GM and lotus. It is not your typicall small block chevy and pretty much nothing on it is interchangable with any other small block.