I don't actually have one, I have a TBI'd car, BUT, I was looking things over and it seems to me that there are a lot of options out there for people with LG4's and the like. If I were to have a carb'd 305 Maro or Bird, would something like the ZZ4, 350 HO, or that new complete 260 hp engine be a direct bolt in for the 305? Are these computer controlled cars? Would there be any issues like that? Or could I find an 84Z-28, take out the old LG4 and replace it with the complete 350 HO and drive it? Can you guys please let me know how involved this swap would be? Thank you in advance to anyone who replies!

 

All 3rd gens are computer controlled (except some carb'd Canadian cars.

There's no such thing as a "direct bolt-in". Get that out of your head right now. Some, however, are easier than others, and without doubt, the 350 HO would be the hardest (because of the Vortec heads).

I'll assume that emissions isn't a problem for you. If that's the case, then the ZZ4 is probably the easiest of the three, with the "complete" engine you're talking about the same but obviously a lower performance choice. Any way you go, you need to completely replace the exhaust, and for that there isn't any difference between the three engines.

There are other small details like flexplate (one- or two-piece rear main seal) that may be different depending upon what year car/engine you get, and torque converter lockup control that will be affected by what type of carb you go with. Tranny selection also can affect the ease of installation.