Originally Posted by beobbys
i have 95 z28 with lt1 knocking wanting to put 93 vortec in its place,will it work?and what do i do about omnispark ignition?
The 93 would be a Swirl Port with TBI (Throttle Body Injection) not the L31 350 inch Vortec which does not become avaialble till 1996 production.
Either engine the LO5 Swirl Port or the L31 Vortec while very basically similar to the LT1 and they will swap as far as mounts, bellhousing and crankshaft hub bolt patterns are concerned the systems that make each of these run are vastly different. There are also substantial differences in engine details of which the LT1 is most different in terms of water pump drive mechanism off the cam, distributor drive off the front timing cover, a very different timing cover and that section of block for mounting it, and of course reversed cooling where the pump discharge enters the block and is rerouted into the heads where it empties back into the block and returns from the block to the pump and radiator through a hot to cold mixing valve.
Of these swaps the 1996 and up L31 is more similar to your LT1 in terms of computer programming and supporting sub systems than is the 1993 LO5. The injection system of rails and injectors can be carried to the L31 with an aftermarket intake or the older TPI intake. But at this point you're starting to spend money. So if the L31 to LT1 swap was seen as a cheap solution, that's starting to fly out the window. You existing computer will support the Vortec ignition as well but some reprogramming will be involved.
Of course you can always scrap the injection and computer controlled ignition and go with a carb and HEI, that would simplify the systems issues a lot.