So I've been scouring the old threads for the last few days and haven't found the direct answers I'm looking for so maybe some one can point me in the right direction or help me out.

Just picked up an 86 720 2.4 with a weber carb already on it but had a bad headgasket. Getting it back together now and I noticed that it has an ecu. Might be a stupid question but is that still necessary? IK the Hitachi was ecc but now what does that do? Does it have anything to do with spark?

I'm pretty handy with motors for having a degree in graphic design and running a sign company but I've done a lot of neons and other 420a cars. This just doesn't make sense yet. Any help would be appreciated.