I bought my MSIIv3 for my '78 Camaro with an LS2 swap into it for $250. (You can buy them new and assembled for like $500??) If you're not running boost or nitrous, which is an awesome application for the 420a (Nitrous anyway). Don't bother with the head studs... ARP bolts will do just fine (my 2c) A MSII will do just what you need... don't forget to either buy the stimulator or find someone that has one so you can test out the ECU functions... If you end up building your own... there is a lot cool extra features you can build into it. (Launch control, boost control, Nitrous safety's... shit like that) I've never been able to afford AEM ECU's (I'm sure they're really good though)